If I understand, you're saying you had sex January 6, then a period, and that your due date is November 11. It would be safe to trust the calculators that say you conceived around February 18. Sperm does not live in your body for over a month.
If you have irregular periods, you could have ovulated late. The ovulation calendars usually go by a 28 day cycle. My periods are irregular and I usually have a 43 day cycle...make sure you take that into count when using those calendars. If you keep track of you periods you can use a period tracker that will determine your cycle length and then it might be easier to figure out when you ovulated.
My LMP due date is 11/11 ... My 8 week ultrasound due date is 11/6. My LMP was 2/4 with 28 days length
I had sex with my friend january 6 and then got my period on the 11 to the 1 of February and then ovulation calender is sayin conceived baby February 13-18
Well I have irregular periods so I had my period for like 2 and a half weeks after the friend
Im 35 weeks and i conceived the beginning of February 2 be honest the only way u can be 100% is by doing a test but if u had your period after u slept with your friend chances are its your boyfriends.
Honestly, you will need a DNA test. It really could be either of them. I went through something similar with my first child, so I've been there. Its rough. Any sex in the course of a month could have resulted in the pregnancy. Have you told both potential dad's yet?