Bleeding in between periods

At first I thought it was ovulation bleeding the first 2 months it happened because I was cramping and bleeding around ovulation time. But last month I didn’t bleed at all so I thought maybe it was the medicine I was taking (metformin for pcos) so I stopped taking it. But now this is happening again (9 days until my period) but with no cramping or anything. And I also have started having my period for 7-9 days when it used to only be 5 days. Bleeding last for only a little bit at a time but it does do it 1-3 days before it stops. And also I have started bleeding after intercourse. Does anyone know what this could be? I’ve had 3 miscarriages and still trying but I feel like this could affect it.