Bleeding whilst taking pill during love making

Patient: Hi I am 38 and had 3 children and i am currently on the Yasmin pill. I have found that when i make love to my partner quite often i will start to bleed , this can be at anytime in my cycle the worst was when i was in the middle of my cycle. Could it be the pill isn’t strong enough for me should i change pills. I do like this one though as it doesnt make my weight change and it doesn’t seem to ggive me headaches like some others, any advice would be appreciated, Oh yes i never seem to get breakthrough bleeding any other time except when my partner and i make love.