Cheap tests off amazon?

Alright so I have successfully missed my entire period. This has never happened to me. I bought an ovulation and pregnancy test kit off amazon and have used a few of the pregnancy tests but all have been negative. I’ve had morning nausea, I’ve been so tired I can barely keep my eyes open, and my boobs get more sore every day. I did experience some cramps yesterday so I thought I would start, but still nothing? Could it be that the tests are just crappy ones? Am I one of the women that don’t find out until like 8 weeks 😅? I would be around 4-5 weeks if I am. Helllpppp lol