So I am 5days post a 3 day transfer, which i got on Thursday with one grade 844 embryo. Today I have a sore back ( which I always get with my period, like a dull ache) I also feel sickish, I am sitting at work and can't concentrate with fear my period is on its way. I'm literally running to the toilet every 10 minutes to check. If it was cramps yes I cud hope it implantation but its not like cramps. Doesn't sound good sure it doesn't?