What can be wrong if I am bleeding between periods and pain after urinating?

Source of blood? If blood is definitely coming from the uterus and occurs midcycle often, it is best to see a gyn provider first. If it is a bloody discharge that could be blood-tinged urine along with pain after emptying the bladder, then seeing a primary care or gyn provider would be a good starting point.
?Gynecologic problem. U should see a gynecologist to rule out uterine problem, likely benign + far less likely a malignancy, but needs to be checked out. May or may not have an associated uti. Treatment will likely by quite straightforward so u + joel can stop worrying!