Am I pregnant

So I had intercourse on July 10th and twice on July 21st. My period is always every 30-32 days but pretty much comes around like clock work. Never am I more than a day late or early for the last 6 months that I've been keeping track. I'm 4 days late and 18 dpo and I've taken 5 tests and there all negative but still not even the slightest sign of spotting or anything. Just wanna know the chances of being pregnant or whats going on with my body. Also I'm super irritable and get dizzy randomly or have a decrease in appetite. Any opinions?