Expert: Dorothy H, LCCE - 7/11/2011

Question
QUESTION: Hello, I've been going crazy trying to figure out/calculate these dates.
I had unprotected sex on 11/25 ... I believe I had a period around the 20th of December, but I'm scared I'm confusing it with implantation bleeding. (I usually get my period around the 20's of each month) I also had unprotected sex on 12/16, 12/27, 12/29, 1/2 1/5, and a lot more days after that. I found out I was pregnant in February. and had a transvaginal ultrasound on February 22, 2011 leaving me at 9 weeks and 1 days. My EDD is September 26, 2011. With this due date, is it at all possible that I conceived on 11/25 making implantation occur on 12/20?

Thanks You!

ANSWER: Based on the information you gave, it is NOT possible at all that you got pregnant from sex that you had on 11/25.

You got pregnant late December/early January, not in late November.  And there is no way anyway that if you got pregnant 11/25 that implantation would occur almost a month later.

---------- FOLLOW-UP ----------

QUESTION: Thanks! I am really hoping it wasn't from the guy I made a mistake with the night of 11/25.
All the other dates were with the man that I care for, and as far as I am hoping, hopefully he is the father. I don't want any surprises when the baby is out, and I wanted to be 100% sure.
So would it be a waste to get a DNA test done? As long as he is for sure the father? Because the bleeding I had in mid-december I believe was my period, but then again I hear you can still have your period if you are pregnant?
Sorry for the many questions, I am a worry wort and very paranoid. I am trying to enjoy my pregnancy, but with all this paranoia, it drives me insane!
Again, thank you for your time!!!

Answer
Ultrasounds at 9 weeks are not going to be over a month off.  There is way too much change going on with the baby.  They can be off by a couple of days, but that's about it.  If you conceived in November, your ultrasound would have shown that you were 13 weeks - which looks VERY different than when you are 9 weeks. There really is no way that the Nov 25 man is the father.  I don't think you need to hope that the man you care for is the father - he IS the father.

Yes you can sometimes have bleeding that could be mistaken for a period. But that would not affect the ultrasound results.  

If the DNA test will give you peace of mind, then do it.  But I have absolutely no doubt that it's going to show that the man you care for is the father.