I do not spontaneously get periods so I have to take progesterone to start my period. After taking the medicine I without fail start my period 3 days after. This time my period was late by several days I tested negative. It started but it has been really light normally my periods are extremely heavy but I haven't even bled onto the pad even a little. Now here is the real weird part my periods are always 7-9 days long. It stopped at 3 days. Anybody have any thoughts? I just started a new treatment cycle with the infertility clinic but my period has never behaved this way