Reoccurrence

hello, just wanting to know if anything has experienced anything similar. Had protected sex with a guy about three months ago and since then ive had a little rash appear at the same place twice before my period and this time also ive had something appear on my thigh.

Not sure if im being paranoid or people do get things that mild but there no other symptoms that are going with it other than these marks that are appearing?

also how do you post a picture to show, tried and it seems to be too big

crop the picture

then this the day after