Do I have endometriosis?

Meadow
So, I'm 16 and I have irregular periods. Not only do I have an irregular cycle, I have severe cramps during my menstrual period, and I'll randomly cramp throughout the month. I also bleed very heavily. These symptoms have been so bad to cause me to even miss school and I'm not sure if it's worth a doctor trip to see. 
Would anyone with endometriosis care to give me their symptoms and their doctor visit experience?
I'm really scared of this and I don't know what to do.