LMP was Dec 21-24 (always a four day period seemed lighter than normal.

Patient: LMP was Dec 21-24 (always a four day period seemed lighter than normal) I had protected sex on Dec 27, although he tried without a condom at the beginning, the condom was a exlrg n he is a little under average I’d say on size.. I also had sex on Dec 31/Jan 1. Im currently 6/7 weeks pregnant according to my LMP.. A ultrasound scan shows about the same..When would I have concieved? I had dizziness, mood swings and semi sore breast between Jan 6/8.. I had a positive pregnancy test on Jan 12/13. How is this possible to know so soon

Doctor: Hello,Thanks for the query,If you had your menses on december 21-24, then the first sexual encounter on 27th dec w as in your safe period and unlikely to cause pregnancy. The next in december 31/jan 1 is likely to be in your fertile period and that is when you should have conceived ideally . The lab based serum beta hcg test can detect pregnancy after 7-10 days of intercourse and is most sensitive. So it is likely that december 31/jan 1 is the likely date of conception.I hope i have answered your query,regards