I need advice..

Hi girls.. I really need advice. My cousin n sister in law think I might be pregnant. I'm having the same symptoms as my sister in law when she finally found out she was pregnant. My symptoms are nausea, headaches, back pain, cramping, and high temp. I am on birth control-have been on it for 4 months now, don't take it at the same time everyday. I have had sex 2x recently. My significant other and I do have a 7m old.. we wouldn't mind another baby, but we would also like to wait. If that makes sense? I'm extremely exhausted.. we had sex a few weeks ago, I did lightly bleed for 4 days, light pink n dark brown. I did take a pregnancy test and it did come back negative. I went to the doctors yesterday and they were only interested in swabbing me for covid... ridiculous. So I could use advice on why I'm still feeling like this? Thank you...