paternity problems

[akb93]

I just found out that im pregnant about 4 weeks ago. I have been with the same man for a year and a half. Between February 20-25 we broke up and I slept with an ex boyfriend. I've never really kept up with periods like I should have and my first ultrasound is this Wednesday. I could wait until then to find out the conception date but I may not even be far enough along to have an ultrasound and I've been worried sick. The man I've been with doesn't know I slept with the ex while we were split, and he thinks the baby is his. We never use a condom during sex, but the ex took his spermicial condom off during sex but claims he never actually came inside me. My concern is that the guy I've been with always came in me and never got me pregnant..now all of a sudden i am..conveniently right after the ex and I have sex. I remember (maybe) having a period march 9. But I don't remember it lasting long if it were a period and read somewhere that you could be spotting the first few weeks of pregnancy. So if I actually did have a period after the ex, then it's not his. But if it were just spotting..it definitely could be his, right? I made a mistake and its worrying me sick. I just need advice and maybe know the right questions to ask the doctor when I have my first appointment.

[AnnieBrooke]

Incidentally, not all doctors do early ultrasounds.  Given that you need the most accuracy possible and the earliest ultrasound possible, it might be worth paying out of pocket if your insurance won't cover it.

[AnnieBrooke]

Dropped a line:

(Later in pregnancy *they are not so consistent,* because babies begin to grow and develop ...

[AnnieBrooke]

If you have been given a reliable due date, you can either count backwards manually on a calendar, or you can use an online calculator that does the same thing.  

But it is only as accurate as the method by which you got a due date.  You can use calculators that begin counting at the first day of your last period, but a) if you don't know when that was for sure, it doesn't help much, and b) if you do not ovulate in your cycle exactly when the "average" woman ovulates, it doesn't help either.

That's why I think you should get an ultrasound as soon as possible.  In the early weeks of pregnancy, embryos are consistent in size and development.  (Later in pregnancy, because babies begin to grow and develop at different rates from one another, so an estimated due date could be up to two weeks off by the 37th week.  But early on, if the ultrasound is off, it is only by a day or two, or by a few days.)  

The estimated due date the doctor or ultrasonographer gives you is based on how the embryo measures up.  You can count backward from that date, 266 days for a count to when you might have conceived, and 280 days to the presumed first day of your last period.

[akb93]

Thank you so much..it's my first pregnancy and I had no clue what would happen at my first appointment. What is a conception calculator?

[AnnieBrooke]

When you go, ask for an ultrasound.  Explain that you were broken up briefly from the guy you want to be the dad, so it is important to you to get an estimated due date.  You can then plug that estimated due date into a conception calculator for an idea of when you conceived.

When you do an ultrasound, they will do a crown-to-rump measurement of the embryo and will assess other measures, and then will tell you that you are "X weeks x days pregnant," and will tell you an estimated due date.  

Keep in mind that the X week x days kind of measurement talks about from the assumed first day of your last period, not the presumed date of conception.  (The kind of count they use is called "gestational age," and that clock begins on day 1 of your last cycle.)  So if they come back and tell you that you are X weeks x days pregnant, it might well count back to March 9.

Drop a line back when they give you an estimated due date based on an ultrasound, and I'll plug it into the conception calculator for you.