Advice please !!!

Charlotte
I came off my pill at the end of August, I've had two periods since coming off my pill, I missed my period last month although after several negative pregnancy tests I am definitely not pregnant. I've since had some pinky spotting after sex and a few days ago random spotting after going for a wee, i noticed some spots of blood on the tissue paper. 
Just wondering if anyone else has experienced anything similar to this? And what it might be?