Help please

Jemma • Been trying since last year had a miscarriage in December :( but trying to conceive again
My boyfriend wears condoms but one split before he cum and now for the past 3 days I've been feeling really sick and today had a pain in my back I took a test and was a bfn I'm 9dpo due for my period in 5 days due on 16th August can anyone help me and when should I test again