How accurate is a transvaginal ultrasound in determining the gestational age of a baby in a mother's womb? I had a one night stand (unprotected sex) with a guy a week before i had intercourse with my bf. But that night he didnt cum. A week after i had sex with my bf but during that time we had a heavy sex until my vagina bleeds for 2 days and we've done it (sex)for 5 times during those 2 days. I didnt know but the bleed seemed to be reddish like a fresh blood. It lasted for a week. I thought i was having my period that time but the bleeding could not be mistaken as my period because normally my period lasted for 2 to 3 days only. And that bleeding lasted for a week a and very light brown color during my last 3 days of bleeding or shall i say it was not really consistent bacause it stopped then after peeing i wiped a small amount of brown blood from my vagina. I was thinking it was just a result of heavy sex and with that i was suffering from a lasceration (correct my spelling if im wrong). I had a trans vaginal ultra sound and the result seemed to favor on the guy a had one night stand with.... That means that it was determined accrdng to the result that the baby's father could possibly was the guy i barely know not my bf. But how come??? That night i know he didnt cum but there was a penetration. Could it be possible that the transvaginal ultra sound is wrong about it? The dates are very exact. Could it be possible that my own bf could be the father of my child? After all, It was only one week difference. Pls. help! Im having dillema bout it. My bf thinks it's his child im bearing. if it's not really his, Is there any chance he'll find out bout it? Both have the same races.....but im afraid the face might not be similar to his.