What are the earliest signs of pregnancy?

I believe I may be pregnant. My fiance doesn't think so but I have a gut feeling that I am. My menstrual cycle has had oddities, I feel fatigue throughout the day, I get stomach sickness throughout the day and I get cramps like I was on my cycle. I have not taken a pregnancy test. I can't afford it right now. But I would like to know what the earliest signs of pregnancy are. Please help?