Abnormal Period?

Does anyone here get quarter or larger sized blood clumps on their period? I've had them for a long time and after I had surgery to remove my uterine polyp, they went away for 6 months, but now they are back. I sit up in bed and one will come out. It feels like giving birth to a large caterpillar! Basically every time one comes out i bleed through my pad immediately. It won't be full. It'll just all come out at once and won't sink in but will run off the edge. This bleeding through thing didnt happen the whole 10 years I've had my period until a few months before my surgery and now it's started again. I just wanna feel like I'm not alone in this and I'd welcome any advice.