I started a new job late August and I notice I haven't had my period since July 11-17. and still haven't had it. I already took 2 pregnancy tests and both came out negative. I've been thinking about a blood test (we are trying by the way). any options?

*I cant see a doctor at the moment because one they are full of other people trying to get in and due to my work, I can't miss any days because I'm on a contract till it's over which won't be till 2019*