Well i started my period around the 24 of January and it ended about the 29 . Well I had sex with my ex boyfriend on the first days that my period had finish which was around 1-5 of February but we used condoms. Well later on like at about 15-20 of February I had sex with my boyfriend and it was unprotected sex. Well when I realized I had a missed period I went to the clinic and they told me my due date is on October 20.. I'm so confused someone help me to know whether it's my ex boyfriend or my boyfriend!?
October 20 corresponds to your LMP starting on January 14 so there is a bit of a discrepancy. I'm assuming you know when your LMP started, that being January 24.
So, using January 24, you would normally ovulate sometime between Feb 4 and 19. Sperm can remain viable for up to about 5 days and your egg up to about 48 hours.
Timing wise it could be either. But, since you had unprotected sex with your boyfriend then he is the likely father - condoms are very effective when used properly.
You need a DNA test to confirm.