Hi,
If you have always had regular 28-30 day cycles, you had the sexual contact during your fertile period. Pre-ejaculate is sufficient to cause conception during ovulation period as it contains sufficient sperm. Since you took emergency contraception within the stipulated time interval, you are amply protected. The nausea and diarrhea you are experiencing are most likely due to the pill effect. You may also see withdrawal bleeding a couple of days later and your next natural period may get delayed by a week or two. Hope this helps.

Hallow Dear,

Your concern is understandable. The fact the precum was deposited on your vaginal opening, the sperms can enter the vagina increasing the possibility of conception.

What you have read is somewhat correct. The the sperms can live for 72 hours. Your step of taking plan B 18 hours after the sexual venture should have given you protection against pregnancy. These pills are very effective. However, the Plan B pills contain higher dosage of hormones and hence can cause nausea and vomiting.

Nausea and vomiting of pregnancy appears about 10-15 days after missed period. It seems you have not missed your period as yet. So this nauseating feeling and diarrhoea could mostly be due to the pills; else it could be due to some gastric upset due to food.

You may take Pantoprazol to control stomach irritation which will take care of nausea. Diarrhroea is usually treated by oral re-hydration therapy. Take Electral after each motion to maintain the hydration. You should feel energetic. If diarrhoea does not get controlled within 24 hours, please report to your doctor.

If at all you miss your period, then you may get pregnancy test done on your overnight first morning urine sample 8-10 days after missing period. Earlier these tests may give false negative results. You have another option of getting Beta hCG test done which gives reliable results even few days before missing a period.

I hope this helps you today.

Dr. Nishikant