Pill help...

I’m currently on the pill (the one you take everyday with no bread, possibly the mini pill?) now and again I’ll get a random bit of bleeding for a few days, nothing major and very light, happens maybe once or twice a year.

Sorry for going into abit of detail here but last week during foreplay with my husband I felt this almighty cramp in my stomach (exactly the same as period cramp) but went away after about 30 seconds, for a few days I had some brown bleeding not sure why but I didn’t read too much into it. Today when I went to the toilet I wiped and there was bright red blood there, however nothing since. Does anyone have any clue what is going on and why this is happening. I’ve been on this pill for probably the best part of 10 years and never had anything like this. It’s not bothering me too much I’m just curious what’s with the random spurts of bleeding.