Help!!

Okay so I am a Virgin. I am in a serious relationship and I wanted to be ready for when we had our first time. Well I bought a dildo recently. I wanted to be able to feel comfortable with the size before I even had sex. Well I've used it only twice but last night I noticed a small bump inside my skin on my labia. I got really worried because it hurts when I touch it. Well I noticed that on the other side I also have this bump on the other labia about in the same spot. Should I be worried or did this happen because I used the dildo which I'm not used to???