Hallow Dear,
Your sexual relationships fall on the 7th day of
menstruation. Usually the egg release takes place 14 days before the next menses; so considering het 26 days cycle, it would be day 12 of the cycle. Egg lives for 24 hours while the sperms are active for 72 hours. Hence day 8 to day 16 would be a fertile period for her. Your intercourse happened just on the borderline days.
Intercourse on borderline of fertile period, delay in menses of otherwise regular menses and nausea &
vomiting are all raising a suspicion of
pregnancy. However, the diagnosis has to be confirmed. Wait for 5 more days and then get urine examined for pregnancy test; done earlier, false negative results may misguide you. Else, you may go for
Beta hCG test which is far more sensitive and specific and gives reliable results even on the day of missed period.
If pregnancy tests are negative and still she does not get menses, give her some
progesterone preparation like Deviry for 5 days and she will get menses 4-7 days after that.
Hope this helps you.
Dr. Nishikant Shrotri