first things first...oct 28th i had unprotected sex w/ a guy around 9 or so. he pulled out before ejaculation, cleaned himself and re-entered for a 2nd time, and again few mins. later pulled out before ejaculation. following morning i took planB, and got my period on the dot as always about nov. 10th, which also seemed very regular with cramping and all. on nov. 22-29th, i had unprotected sex again, but this time allowed him to finish inside every night we were togther. we were trying for baby. never got my dec. period, but the wk. i should have had it, i had the worst cramps ever, and just once or twice did i see spotting, so i assumed it was coming. my periods are always on time...they never fail. i am about a 30 day cycle, but it never really did. well...on dec. 15th i was considered about 5 wks pregnant by u/s with a sac but no baby inside. sac measured to be about 5wks. doc. said it could be either too early of pregnancy or lead to a miscarriage, which is why there is no baby. on jan. 22nd another u/s showed 2 sacs each with a baby, and gestational age measured them to be about 10 wks. I was told that this pregancy is from the sex that occured between nov. 22nd- 29th, judging by my LMP and u/s. is this correct? is the gestational age in an u/s measuring from LMP too? could i please have an answer quickly...because this is my 1st pregnancy and it is all quite confusing!!!