Need help!

K so I had surgery for endometriosis on the 31st of December because I went 2 months without a period and lots of other things, got my period the 1st of January (which before my periods stopped was my correct date). We have been trying and AF hasn't came yet but I've taken three pregnancy tests and all negative one sunday morning and two Saturday night. What do you guys think this could be? I have had pregnancy symptoms like ALL of them ha.