I'm 21 years old I was wondering I'm trying to get pregnant and I cant... it because my period its irregular it come on twice a years... do you think it's that or it could be something else

If you only have two periods a year, you will have problems getting pregnant. Have you had any tests done to find out why you have so few periods?

Most likely that is exactly the reason. How long have you been trying to get pregnant? It can take quite some time, even for someone with regular cycles.

Time to see your doctor to find out whether you are ovulating at all... if not, you wouldn't be able to become pregnant without some medical intervention.

There are means to help regulate cycles and to induce ovulation that they can discuss with you if appropriate to your situation.