Longer periods

Hello fellow ladies. I have a question. I’ve been on lo loestrin fe for a couple of months now. I’m taking the lowest dose once a day. However instead of reducing my pain pain, which is the reason my doctor prescribed it to me, my periods have be lasting longer. My last period was near 14 days. Has this happened to any of you? My doctor says it’s normal to have irregular bleeding while on this pill but I find it super inconvenient and annoying. Thoughts?