I'm 23 and I have irregular periods. Sometimes I get them after 2 months, sometimes it's 4 months between, and there's been cases where it's been almost 6 months. So I never know when I can get pregnant. I had sex 13 days ago and was wondering if it's too early to take a pregnancy test. If my period was regular, I'm 7 days late. Since I'm not, I don't know when implantation occurs or when I should be expected to know if I am pregnant. How long could it take to know if I am pregnant?