Radiation exposure

My peak fertile day was yesterday and husband and I had intercourse. This AM I checked my cervical mucous and noticed it was slightly pink.  I have never been this in tune with my body, we have two daughters already, but now that I am a Radiologic Technologist I want to know very quickly if I am pregnant.  I was a SAHM my last two pregnancies and now work full time.  I am very cautious of my radiation exposure but I do get some.  My question is, how soon can a blood test be taken to detect pregnancy?  And are there any radiology employees that have had any complications due to exposure?  Thanks so much for helping!!!