What is wrong with me?

Hi. Well I am a healthy young woman of 24 years of age. I have two children and both are healthy. I have no known health problems at this time. I'm not currently on birth control and haven't been since february, but my husband and I don't have sex but maybe once or twice a month.

I had a normal period and it lasted seven days. There was nothing abnormal about this period. Two weeks exactly after my period had ended, then I started spotting bright red blood. It's enough to wear a panty liner. Anyway, there is about 5-6 drops of blood in the toilet and then there's blood on the tissue when I wipe.

Does anyone have any ideas on what could possibly be wrong with me? I went to get my yearly woman's appointment visit over and done with the next week after my period had ended... And it all came back normal. Then the next week is when I started spotting. Can anyone tell me what could possibly be causing this? It's not birth control because I haven't started putting on my patch since I have to wait until my next period. My mom said it could possibly be a miscarriage or a tubal pregnancy. Can anyone give me their ideas on this?

Thanks. All answers are appreciated!