Keppra causing irregular periods

Hi all, I am 27 years old, and I started taking Keppra on 11th April for the first time. I'm still getting used to it, gradually increasing my dosage. I'm currently on 1250 mg. Here's my story. I was supposed to get my period on 2nd May. Instead, I started spotting earlier (20th April) (back then I was taking 750 mg a day). The spotting was really light and it stopped after 2-3 days (I could have gone with only one pantyliner). Next week, when I increased my dose to 1000 mg, I've started spotting again. It was also light and stopped after a few days. I didn't get my period on 2nd May as I was supposed to. 4 days ago (12th May), I started spotting again and then two days later the flow started getting heavy, but without any period symptoms. I'm not actually bleeding, there's usually nothing on my pad, but I can see the blood on my tampons and I'm passing blood clots while urinating. There's no cramping at all. Although the chances are small to none, I even thought I might be pregnant. Did anyone else experience this with Keppra? Could I be pregnant? I didn't talk to my neuro, but I did call my gyno, who wasn't very interested in the topic and told me that any new medication can cause irregular periods. My periods are pretty regular and I've never experienced spotting before this. Thanks for the answers in advance!