Hi and thanks for your question. This must be worrying for you.

While it's unlikely that you could be pregnant from this situation, it is possible. Pregnancies have been known to happen when there has been sperm on the vulva and the woman is at a very fertile time.

This is because when a woman is fertile she produces a special type of mucous, which makes it easy for sperm to enter the vagina and make their way up into the uterus (womb), find an egg and fertilise it.
While it's hard to tell if you were in a fertile time or not, if you have a regular menstrual cycle and you were right in the middle of it then it's more likely.

If you had been on the contraceptive pill for a while (at least 7 days of hormone pills) then you should be safe and protected from pregnancy, even though you missed a pill that day.

There are other reasons that you may have missed a period, however it's important that you do a pregnancy test as soon as you can and find out. You can usually get pregnancy tests at pharmacies in most countries, but otherwise you will need to see a doctor.

If you are not pregnant, then either stay on the pill if you have not stopped it. Or, if you have stopped it, wait until your next period comes, then start it again on the first day of your period by taking a hormone (not sugar) pill, then wait 7 days before having sex.

Remember that you will need to use condoms to protect yourself from sexually transmissible infections because the pill will not protect you from these.

All the best and take care.