Can Myomectomy Affect Menstruation?

Had a myomectomy in June. July August and September were regular cycles October and November were not normal. Cycle came early and not flowing. I spotted and cramped bad in October but not really in September. I knew my cycle was here due to the cramps, when I went to the bathroom and also when I wiped. I have taken a home pregnancy test but negative. Can some else be wrong? Your thoughts. Thank you