Suggest Remedy For Irregularity In Periods

I was taking clomid 50mg for a few months and had normal periods starting around day 30-31. My doctor increased the dosage 3 months ago to 100mg and since then my periods have been a lot different. Last month I had spot bleeding for one day on day 27 and this month I started spot bleeding on day 20. I have not had a full blown period like I'm used to having. I took a blood pregnancy test last month after spotting and it came back negative. Is this normal on 100mg clomid?