Too much sex?

So my bf and I have been going through a Phase where we just can't get enough sex lol anyway we have been having sex about 2-3 times a day and every single day for about 9 days now. 
I have developed like a ball under my skin on the side of my vagina where the hole is. (Only way to explain I don't know all the terms lol) 
It's kinda the size of a ping pong ball if I push up and feel it (I know gross) it's throbbing a bit and it's uncomftoble. 
Anyone had this before?