Until I started actively trying to get pregnant, I didn't really truly understand how complicated and iffy the whole thing is. I've been a volunteer for Planned Parenthood since the 1992 Republican national convention. I've been on many types of birth control. I've led some sex education classes. I've practiced a lot. I've considered myself fairly knowlegeable about the whole process. I didn't realize how spread out, over almost a week, the timing between having sex and "being pregnant" (whatever that means) was. And I had always thought that in order to get pregnant that ovulation happened BEFORE copulation.
Fortunately, around the time we started talking about "hey, maybe it's time to get off the pill", this post was published at Obsidian Wings.
And, a few months later, we started "trying". Which generally involves a lot of peeing on sticks and taking my temperature in the morning and then timing (more) sex on days when charts and graphs and hormone levels and the stars are aligned.
There's this rough window of about six days when I may
be fertile. Five days before ovulation, and maybe the day of. Based on the calendar estimation of things, it should start about eight days after the first day of my last period. But because I'm weird, my basal body temperature doesn't start dipping until thirteen days afterwards.
But this is the salient part for us:
That is, you get pregnant by having sex the day *before* you ovulate, not the day you do. Summarizing a bunch of technical talk: sperm are fairly tough, they can keep swimming in a congenial environment (like, say, a woman's Fallopian tubes) for maybe 4-5 days. The egg, though, has to delicately balance a huge number of processes at once. She can't move very far or fast, and she doesn't stay ready for action for more than half a day at the outside, often only for 6 hours or less.
So basically, in order to get to a pregnancy the sperm have to be all in place, milling around in the Fallopian tubes in their microscopic Speedos, elbowing and trash-talking each other (the technical term is sperm competition), while the egg is putting the final touches on her makeup and balancing that damn bird on her head. (ed note: There's a picture here in the original post)
When she finally heads out the door to the party (ovulation), the guys need to be there already. Then they can meet up and seal the deal within a few hours: conception. The zygote (aka "fertilized egg") then moseys down the Fallopian tube and into the uterus, dividing all the way, and then finally lands on the uterine wall (implantation), which is when pregnancy begins and the woman's body starts changing.
So we have lots of sex and hope for the best. But there's that period between sex and ovulation where everything is just iffy. Fertilization doesn't generally happen until a day or so after sex, sometimes more. And then implantation doesn't happen for a few days after that. Even then, only 20 percent of the time does this process work all the way through.
Now-ish, I'm in that weird no-man's (heh) land between ovulation and (possible) implantation, and for roughly two weeks every month, I have no idea if I'm pregnant or not, and there's no way to tell until next week if I skip an expected period and a pregnancy test comes back positive.
BUT, according to the way we calculate pregnancy, if I am pregnant, I am already over three weeks pregnant, even though I didn't ovulate until (probably) six days ago. And the relevant sex could have been as far out as 11 days ago.
So if I am pregnant, I won't know which of several attempts caused the pregnancy, and I have absolutely no idea when "conception"--or, the term I prefer, fertliization--occured. Fertilization doesnt happen until usually at LEAST the day after sex. Pregnancy, as defined as "pregnancy tests come back positive and the human body has started adapting itself to have this foreign body in it for about 37 weeks", doesn't happen until implantation.
So going back to the Dr. Science posted above, the sequence of events is:
So the sequence is:
- a day or more passes
- a few hours pass
- about a week passes
- implantation begins
- a week passes
- pregnancy test comes back positive
And of course, this is all plus or minus depending on a whole laundry list of circumstances. I didn't know the details of this before last March, mainly because until then, I pretty much wanted to stop the whole thing at step one in the list above. And I like to think of myself as fairly sophisticated on human reproduction with more of a bent of looking at the whole thing as a process than some magical moment.
So I'm not terribly surprised, given my own ignorance of the process, that there are a TON of people out there that have no idea how the whole process works aside from the basic "sex-->fertilization-->pregnancy" thing. And that's the people without some sort of ideological agenda that they want to insert into this process.