Itchiness

Okay, I don't know if this is possible or not, but after getting the shot for birth control. I started spotting which is perfectly normal. What the problem is, is that I'm noticing that Everytime I spot. It itches like inside my vagina not outside. It's sooo irritating. I don't know if it's the shot or maybe something else but I haven't change anything different with my soaps or anything. It itches really bad.