Day 3 missed period. Help?

Destiney

So me and my fiancé have been trying to get Pregnant for a while and have had a couple false alarms, but now I’m 3 days late, and having bad cramps, headaches, backaches, and I get dizzy throughout the day. I took a test on the morning of day 2 of my MP but it was a faulty test. What should I do?? I’m so nervous.