I am rh- and pregnant with my second with my first my blood mixed I also have pcos I'm 7weeks what's my chance of misscarraige?

Rh negative. The fact that you are currently pregnant should not worry you at present about pcos. Pcos usually causes a temporary infertility, or anovulation. Get screened for gestational diabetes. Regarding your rh (-) status, your doctor should check your baby for a condition called "isoimmunization." you should have gotten a shot called Rhogam during your 28th week of pregnancy during your first one.
Rh & PCO Risks. The rh should have no effect on the miscarriage rate. If you were sensitized last pg then you need mfm doc. If you have pco and you are 7 wks pg then you are at some increased risk of miscarriage from pco. An us exam would be very helpful to predict the outcome of the pg as a fetal heart rate is very reassuring and the loss rate is only about 3-5%. Good luck.