Lately after unprotected sex my vagina has been hurting and burning. I just got back with my ex. Also he has been on HIV websites. Should I get tested?

Get tested/ see GYN. As with any painful process you should seek medical attention. Painful intercourse is caused by any number of reasons. Of some particular urgency is establishing your HIV status as well as that of your ex or any intimate contact you've had unprotected relations with. Until both of you determine your STD status (including of course HIV) you should NOT HAVE UNPROTECTED SEX until then!!!