16 days late

So me and my fiance have been trying to get pregnant for 4 months now. We've had 13 negative tests 1 indecisive and 1 positive. When we got the positive on I went down to the pregnancy center, but their test said I was negative. I am now 16 days late for my period. I want to test but I don't want the disappointment of a negative test or get my hopes up if it says positive and I'm not actually pregnant. What should I do?