I am 18 years old and I m 5 7 148lbs.... Well I started spotting around the 23rd of last month and kept spotting for 3weeks, then it stopped for 2-3days then I started bleeding very heavily for a week and a half and it stopped 4 days ago... now I m starting to spot again... Also I ve noticed on the left side of my lower stomach below my bellybutton I have this unknown mass (I think) that s been forming since the first weird spotting and now it s noticeably bigger like the with of a baseball.. doesn t stick out like one but is just the with.. My husband has even noticed it before I said anything.. I know I m not pregnant , so what could it be??