What Causes A Scanty Menstrual Period?

I am 24 yrs old, 215 lbs,5'5" and I have had one child by c section. I never get regular periods, maximum four for the year sometimes none. but recently i have started what i think is my cycle but it is coming so slowly- that is maybe a tablespoon the whole day. I generally get cramps a few days before and for the duration of my period but not this time, I feel great. I have not been sexually active for the past 2 years so I am sure this is not the spotting or breakthrough bleeding some women get when pregnant. someone please help me! I am starting to diagnose myself with all types of illnesses!!