I have a pain in my vagina, sex is uncomfortable for me and painful and i already had my period. should i be worried?

Get checked: Sounds like you need to see your GYN. You may have some sort of vaginal infection.

Get it checked out.: If this is a new pain, and if it continues to happen, you should definitely get it checked out by a gynecologist. It may just be a matter of inadequate lubrication but you may also have a bacterial or yeast infection that can cause local pain/discomfort with sex. If you are using latex condoms, you could have a latex allergy. So don't ignore it.