Hi i have a regular 28 day period every month and for the past 7 months i have passed 4 decidiual casts . I have three children and am on contraceptive pill .My gp tells me this is normal and they dont have any answers and have not heard of my case before . This decidual casts falls out on the first day of my period every second period.My period usually comes on time every month with no heavy bleeding , no pain, but this month i was ten days late with a negative pregnancy test on day 5 of missing period. I would like to know if this is normal and if not, what should i do ? As my gyno said she hasnt heard of this before and is clueless.