Thank you for visiting the EmpowHER community and for sharing your question.
The days in which your starting point will vary as there isn't an even 30 days in every month.
I am sure you are really stressed out about your late period. Try to relax and take a home pregnancy test to find out whether or not you are pregnant.
The birth control pill is a very effective birth control method, but it is not 100% full proof even when taken exactly as prescribed.
Less than 1 out of 100 women will get pregnant each year if they always take the pill each day as directed. About 9 out of 100 women will get pregnant each year if they don’t always take the pill each day as directed.
There's definitely a chance that you could be pregnant if you had unprotected sex during your fertile window and he finished inside of you. It's not very common, but possible since you missed your pill by 5 hours.
The best way to know is to take a test tomorrow morning with your first urination.
I wish you the best. Please keep us posted.