Constant Dull achy uterus???

Pretty much all day I have a full achy uterus or really just behind central area on uterus. What's that about? Back ache and headaches. Last night almost threw up at the restaurant bc of different smells. Constipation the diarrhea and last week I bought a completely random cold. No period, no spotting, just white discharge. Mild fatigue too. I'm 19-21 dpo and no period in sight. The kicker.. Still no BFP! This has never happened to me before. Any thoughts? I just ordered 10mlu pregnancy test. And setting up appointment for next with doc.