Do I have my period? Please help!?

I'm 14 and have had discharge for about 6 months. I went to the toilet two days ago and I peed blood, basically but when I wiped there was not blood, and there wasn't any blood on my undies. I told my mum and stuff, and i wore pads because I thought it was my period. The same thing happened when I went to the toilet during that day, but still no blood when i wiped or on my pad. That night my stomach was grumbling a lot and i had a few cramps. The next morning the same thing happened as the day before but my stool was also blacky-purpley colour. (weird) After this, nothing happened. There wasn't anymore blood when I went to the toilet, and there was only normal discharge on my pads. (This is the 3rd day since this started) I'm really confused about what this means, and if its my period. Please help me!