Whenever the natural hormonal
cycle is disturbed by an external means, it takes a couple of cycles to return to normal pattern. Also, post-hormonal periods could be heavy a couple of times. Condoms have a failure rate of up to 15%, so, if you have not yet seen your period, you can get a pregnancy
test done after a few days and see. If you wish for a better confirmation, you may go for the blood test
and a trans-vaginal sonogram and see a specialist for an opinion. Take care.