Miscarried at 16 weeks and d&c 3/14. period 4 weeks after, but now been 35 days no period (longest ever). neg. pregnancy test. what could be wrong?

Track over time: Give things a little time to get back to normal. If your cycle continues to be irregular over the next few months schedule a visit with an obgyn

Anovulatory bleeding: Pregnancy is always on the list of possibilities when a woman has abnormal uterine bleeding or cycles. You may be having anovulatory cycles (cycle without producing an egg from the ovary). If a urine pregnancy test is negative, i would recommend evaluation by your gynecologist, and treatment will depend on the cause of the abnormal bleeding and your current short-term pregnancy goals.

Menstrual calendar: wait 2 weeks and see if it is just a hormone related issue. I suggest GYN evaluation and blood testing if no cycle in 2-4 weeks.

Nothing: Not to worry. You have had 3 things that can effect your cycle. 1. the rapid hormone changes of losing a pregnancy, 2. the emotional effects and 3. the effects of having a D&C. Good health