I had a miscarriage baby measured 13 weeks is there any chance my sleeping tablet caused this i only took it once 50ml dipenhrydramine hydrochloride:(?

No: No, a pregnancy wouldn't miscarry just because of diphenhydramine. Miscarriages are a normal part of having children, so many women have a miscarriage while creating their family. Some pregnancies make it to term, but others do not (that's what naturally happens). The Ob-Gyn doctor can investigate as to why, if he or she suspects an unusual problem causing the miscarriage.