Hi. I'm 18 And Was On The Lo Loestrin Fe

Hi. I'm 18 and was on the Lo Loestrin Fe birth control. I stopped it about 6 months ago and haven't had many problems besides sometimes lack of a menstrual cycle. I started bleeding March 10th and then stopped April 1st. I had cramps and felt some sharp pelvic pains. The bleeding was a lot lighter some days than others. I started bleeding again on April 3rd and don't know what's going on. Is it a hormone imbalance?