Period.. sex.. then cramps.


I am 5 days late for my period, I had sex today and straight after I had sex, I had mild cramping, but after half an hour of cramping it stopped, I thought my period was going to come but it obviously hasn't, I've taken at least 25 pregnancy tests in the week, some of them had positives and some was negative.. so I have recently gave up on tests for now, but period has not showed up for 5 days, and also I had clear stretch mucus earlier, and now it's just sticky, can anyone give me advice on this please..

Could I be pregnant?