Pregnancy and periods

Rebecca

Hiya, ttc after being told I have endometriosis./ I am 25 years old. 2 months trying, first month period came early. This month I’ve gone by the 28 days and today is my 28th day; I tested yesterday and negative. No period yet, when shall I re-test? What’s the likelyhood I’m pregnant? I hate seeing negative! 😢