Questiondear Brenda i found out 4 weeks ago i was pregnant, thing is i foolishly slept with some one else and need a second opinion as to which 1 is the father i have been doing alot of resarch and i am 90% ceartain i no who the father is. here are the dates hope you can help... (i have 28 day cycles and im like clockwork) the first day of my last period was the 26th of january, i slept with someone on the 8th of feb, (the day before i was due to ovulate) but i also slept with someone on the 16 0f feb. i have worked out that the guy i slept with on the 8th is the father due to the date of ovulation being the next day and the fact that i was told on friday the 28th of march i was 7 weeks and three days pregnant there was a heartbeat on screen and the crl was 11.5, if it was the other guys then i would have only been 5weeks and 6 days. and i have read that the crl at that time is only about 4.5 and that there is usually no heartbeat.. do you think i have correctly put everything together? i realise you would probably prefer not to say for deffinate but do you agree that the person i slept with on the 8th of feb is most likely the father?
AnswerDear Alice,
With the LMP date of 1/26 and a history of 28 day cycles, I calculate that you most likely did ovulate/conceive on 2/8-9. However, that dating puts you at 9 weeks, 1 day today with a due date of 11/1/08. If your scan on 3/28 dated you at 7 weeks, 3 days, that actually indicates a 2/19 conception date. All pregnancy dating is based on LMP and assumes a LMP two weeks before conception.
Your CRL measurement of 11.5 mm would seem to indicate an approximate 7.5 week pregnancy. The average CRL for 8.5 weeks would be 19 mm and for 9 weeks would be 22 mm.
Therefore, I cannot tell you definitively which to conclude as far as who the father would be. I would be asking your doctor if the initial scan was conclusively a dating scan.
I hope this has helped you and answered your question. I wish you well.
Brenda
