Prednisone.????? help

so I hurt my shoulder and went to see the orthopedic Dr today and they want me to start Prednisone... apparently I have bursitis.... but Prednisone is not safe to take in 1st trimester, I took a test at the office and it was negative but it's still a week till my period and my bf and I have been ttc, so i don't want to start the med yet, just in case I am.... praying for my BFP, I was super disappointed when the test was negative today... currently 6dpo... any help?