So me and my partner was having absolutely amazing sex and after he finished inside me I started to notice it stung down there.

We have sex very frequently. At the very least once every other day and depending on our mood (because we found some amazing ones we like) we may or may not use a condom. So its more like 40/60. 40% chance we wear a condom. And he comes in me basically every time (because I'm on the shot and we both find it sexy as hell), and it never bothered me before.

Why did his semen bother me now?

I know its not some medical thing because like I said we do this a lot. One time we did it three-four times in a day and it only hurt a little, different from this pain, from the friction. So I kinda know the difference. However this pain is very new to me. Should I be concern? Should I see a doc or see if it will go away on its own in a few days? Should I tell him?