Could this be serious?

Recently (within the past couple months) my vagina has been itching uncontrollably a day or two after I have intercourse. I've been with the same guy sexually for a little over 3 months. Could this be something serious? Should I go to the doctor? Or am I just overreacting? I was trying to avoid the doctor but if y'all think it could be serious, I may need to get it checked out...