Hi.I Am 37 Years Old With No History Of Pregnancy.

Hi.I am 37 years old with no history of pregnancy. this is 9 day of blastocyst embryo transfer.from day 2 I had sever uterus cramping at night and I felt vibrating in my body. at day 7 I had lower back pain.but now I have no symptom .not pain not cramping and I lose weight about 1.5 killos.and I have been diarrhea from the first day. Are these normal symptoms ?I am worry about that. I am in natrul cycle embryo transfer and just use progestron.thx for your attention.