Wondering...

I have light cramping, nausea, gassy, and I think I'm late. I'm sensitive to certain smells and woke up last night because of something I smelled in our house. I took a test two days ago and it said negative but I read maybe levels could be low and to retest later. I don't track my periods like I should so I'm not really sure but it was early to mid month last month. I'm not sure how long to wait to take another test. Any suggestions or comments???