What is this!?!?

Right so i've just finished my period around 2 days a go and had an intercourse with my partner, my lower abdomen felt very funny afterwards but it didnt last long. The next morning i went to the toilet and i found THIS unknow thing when i was wiping and it absolutely scares the living hell outta me.. does anyone know what this could be?? And im on the pill idk if that's related.