Tender breasts heaving while brushing teeth negative test?

I have been feeling quite strange lately. I have been slightly nauseous, really tired, have numerous but mild headaches, breasts were slightly tender but that went away, I have had period like cramping but it feels slightly different than normal and every time I run to the bathroom because I feel a slight trickle and think I must have started my period, but no blood, I have been bloated, my lower back aches and I’ve been eating a lot more. This has been going on for about two weeks. I had unprotected sex three weeks ago. About a week after I did so, I took a pregnancy test, mind you my periods are irregular, but nothing showed up in either window until like eight hours later. It came with two in the box (they were rite aid brand hpt tests) and around the end of week three I took the second one. There was no evaporation line no matter how long I waited but a negative result. Could I still be pregnant? The test was pretty cheap and the first one was defective I believe. But im just not sure. on top of that, this morning I woke up and I couldnt move because it felt like my room was spinning and I knew I was going to hurl. I went to brush my teeth when I finally managed to get out of bed and started dry heaving when the toothbrush touched my tongue. later in the day I threw up three times and I could barely move without the feeling that I was going to pass out. I was very frightened because I’ve never felt this way before. ps. sorry for posting this again I didnt know how to add to it.