Pain when I masturbate-Should I be worried?

I don't know how to phrase this, but when I penetrate myself during masturbation my the right side of my pelvis hurts - it might actually be my ovary because the pain's in that area. The pain starts to occur when I feel more pleasure. I've been able to orgasm, but not how I used to because I stop because of the pain. I think it may be because of the form of contraception I'm taking (the Evra patch) because the pain started happening then, but it's not listed as a side effect. I won't be able to see a doctor in the UK until mid September because I'm abroad at the moment but should I be worried? I don't experience the pain when I'm not masturbating, it's just really annoying because masturbation is now not a pleasant experience and I don't really experience the same amount of pleasure anymore, even though I would do if I didn't experience the pain.