Taking 100mg my period started on the 18th and ended on the 23rd took my clomid (clomiphene) for 5 days starting on day 5 of period week later spotting again. why?

Effect of Clomid (clomiphene): One possible side effect of Clomid (clomiphene) is that it can thin out the uterine lining (temporarily) and make it more prone to bleeding. If your lining measures <6mm then it's very difficult to conceive. Also, right after the LH surge (signal for ovulation) there is a dip in estrogen levels and some women experience spotting at that time.