Could stress cause me not start my period on time. My periods haven't been on time all the time after I had my daughter and I can't afford to get on birth control yet and my boyfriend and I don't use condoms.

You. You can get free condoms at most clinics, such as planned parenthood. Hormone changes can cause late periods, but since you are having unprotected intercourse then you should take a pregnancy test to be sure. Please be seen at a clinic and have them advise you; there are many means of free birth control if you desire it.