Could I still be pregnant?

I stopped breastfeeding 9 weeks ago & had egg white mucus on Tues 6th October. This is the first time I have seen this discharge since before having my little girl.

I had unprotected sex on Sun 4th October & have still not got my period back from having my 15 month old due to breastfeeding for a year.

I have been feeling sick, sore boobs & got bigger, my tummy is bloated & i’ve been having vivid dreams. I gagged on an omelete yesterday & generally feel pregnant like I did before. I done a cheap test at lunch time & it is negative.

What could be happening...Could the HCG levels not be high enough for a pregnancy test to pick up yet as I have no idea when i would have ovulated?! So confused 😕.