Possibly Pregnant?

So I was supposed to start my period on 2/5/2020 and I still have not received it. I was given 2 HCG blood tests by my doctor a few days before and a few days after and they both came back negative. I wasn’t stressed and was actually prepared for my period to come. Is there a chance I could be pregnant? If so when can I try to take a test to find out?

BTW- husband and I don’t use protection and I’ve been off birth control since November. But I did have an ectopic pregnancy back in June 2019 and got my right Fallopian tube taken out. I didn’t have my period in Nov/Dec of 2019, got it Jan 2020 and nothing yet as of Feb 2020