Not sure if conceived?? Help.

Natalie • I`m 30 years old and been with my boyfriend for 2 years, been trying to conceive for 4 months
Please would anyone be able to help my confusion. We've been trying to conceive for 8 months. I've been showing signs of pregnancy for a few days, nausea, cramps, hot flashes, tiredness and sore breasts. I've took a test and shown negative. Is it possible to show signs of pregnancy before it can be detected on a pregnancy test? I have irregular periods so can't say if I've missed a period as I know that's usually the biggest detector.