I just started Ritalin about 2 weeks ago. A week into it, I start my menstrual cycle and I notice my ADHD more even though I'm still on Ritalin, I read another post, so I figure it's due to the hormones and after a few days (when my period was no longer heavy), those symptoms improved. But normally I have a long period (7 days), this time my period lasted for 3. I'm not complaining (just hoping it's not due to a physical problem) but has anyone noticed if their period days decreased?