uti???

so the past couple days it stings a little when i pee but ONLY after sex. it’s not super painful but it stings. it feels almost like when you have a cut and put hand sanitizer on, like it stings mainly in one little area. it doesn’t sting or hurt when i pee any other time besides after sex. my friend told me that i would know it’s a uti because it hurts really bad but to me, it’s not super painful, and i have a low pain tolerance. i told my boyfriend and he thinks maybe it’s the cum that could be causing this but i have no idea what it could be...any ideas?