Clomid change your cycle?

Hello. Last month I did first round of Clomid after doing three rounds of Femara. I did finally get a good progesterone level 6 DPI, however I got a positive peak opk on cycle day 18 which is 4 days later than usual but my period started CD27 which is a day or two earlier than usual. Has this happened to anyone else on Clomid? What is the point if my LP is now too short? Thoughts? My doc does not seem worried as this is the first cycle and I am 4 months post miscarriage.