Yes, I had a similar situation when I stopped taking allergy pills. My period length increased by 12 days than usual, and I was very scared. I thought I had something with hormones. I even started using the
Women's menstruation calendar online [womencalc.com] to track my every day and how my menstruation is going. Everything worked out by itself, but I had to wait about 3 months to restore the cycle. If this has been going on for a long time, you need to go to the doctor and take tests for some hormones. I hope u gonna be okay!