If you conceived in march you would be 24 weeks not 12…don't you mean MAY??
Conception May 28th
No I was 22 weeks yesterday, but on my first scan judging by the dates they gave me my due date is december 16th 2011 and I would of got pregnant March 11th, but conception calculators online and my doctor said I would of conceived around 20th - 28th march?
What was the date of the ultrasound? If they put u at 12 weeks 5 days then count back 10 weeks 5 days and this date would give u the conception date give or take a day or so.
The important thing needed is LMP. Be warned though it's extremely doubtful we can give you an answer. You slept with these guys 4 days apart, and nothing but a DNA test will give you an answer.
When I did a conception date based on your due date, it's gives your LMP as of March 11. You wouldn't have gotten pregnant then, pregnant is just dated from LMP because doctors don't know when a female ovulates.
If you had multiple sexual partners within a close period of time you can't go by what the guessed conception date is. You'll need a paternity test. Sperm can survive inside a woman for up to a week waiting for an egg to be released.
If you slept with more than one man within a week of ovulation any of those men could be the father. Let them all know and once the baby is born get a dna test done.