Two periods in one month, this is urgent, help?!

Basically, in January I had a period on the 6th and then I had one on the 31st too! So that two periods in one month! Now it's the 19th of February and I haven't had a period yet! Between those dates I had unprotected sex once, but.., he did not ejaculate in me as he says and I knew he didn't, but I'm just worried as I am not on my period yet, and advise or help, thanks. Also why two periods I one month?!

First of all, the "withdrawal" method is not effective. You can still get pregnant even if he pulls out. You only need one sperm to hit the target to get pregnant, so don't have unprotected sex unless you're ok with getting pregnant.

A doctor should answer the rest of this. Can you call your doctor's office to talk to a nurse/the doctor? If not, Planned Parenthood has a free women's health chat line where you can get answers from a health care professional:
http://www.plannedparenthoodchat.org/