No period last month had unprotected sex all last month and month before but period came 1st of this month .. do that mean i can't get pregnant ?

Explanation : No. It doesn't mean anything. For any professional answer we need to know a lot of your medical history, sexual activity, BC pills and so on. You too young to worry about this now.

Irregular periods: Irregular periods are one of the most common problems obgyns treat. If this is one time problem it usually resolves on its own. If this is a recurring problem you should be evaluated. Infections & hormonal changes can cause spotting. If there is a concern for pregnancy then do a home pregnancy test . There are many options available to help regulate the menstrual cycle. Schedule a visit.