Bleeding after masturbation?

[Aocchi]

I never thought I'd be asking advice on this but... I'm a 20 years old female, virgin. I think I've first masturbated about 5 years ago and I'm sure I've already broke my hymen since then as I've been using both my fingers and toy replacements for a long time. Since about a couple months though, I keep bleeding after I'm masturbating/orgasming. If I'm using a toy it's a couple drops of blood, if I'm using my fingers it's usually half of those covered in blood. I thought I might have scratched myself and stopped doing it for about a month (I've been feeling ill anyway), trying to be less rough etc. but it doesn't seem to help.

The bleeding never persists. It's just the blood then, bright red, I wipe it off and that's all. It is only after orgasming, I've checked. I'm not sure if it's related to my menstrual cycle or to birth control pills (I have to take these for hormonal problems, although it's not the first time. I've been on and off them for 3 years or so and this had never happened. I wonder if it is because I've also recovered from an ED during this time and started getting heavier periods as well compared to before.) but I just want to hear some opinions.