Frustrated

Hi I was wondering if someone could offer some advice my husband and I have been ttc for almost 4 years now and have no issues with fertility. We have had times where we have thought I am pregnant because of being late and all other symptoms only to be disappointed. The issue I have this time is that I am now 6/7 days late and I have done two tests one on Monday and one on Tuesday and both said negative I am having cramps nausea and extremely tired. I have lots of signs saying yes including the late period except for the test. J don't know what else to do and I am quite concerned as I am on a lot of extremely strong medication would you wait a little longer to try a test again or wait for af to make an appearance or make an appointment with a nurse at the gp surgery please help I have had so much disappointment over the last 4 years I don't know how much more we can take and I am not eligible for help as my weight keeps fluctuating up and down.