I am trying to get pregnant. I have been trying for a couple of months now. I have a period every two weeks recently but I have taken test and they all say negative. I had unprotected sex about a week and a half ago and then had my period but it was only two days and very light. What does that mean and since I have periods every two weeks when should I test myself.

A non regular period makes it harder to track your cycle. And while some get pregnant the first time they have sex, it can take some couples months, even more than a year to get pregnant, having their timing perfect

Having periods every two weeks is really a problem that should be looked into by and OB/GYN.