Help!

My period is 5 days late, I’ve never had a late period.. I’ve bought 2 cheap test but they both came back negative, I’ve had on and off nausea and light cramping with shakiness. I went off my BC for 30 days do to health issues but was back on again after that month. I had a period last month and after my period I had unprotected sex with my boyfriend. I’m not really sure what’s going on with me!