Got two clear blue digitals saying pregnant and bloods last week now two clear blue digitals saying not pregnant

Can someone please give me there option on what could be going on I’m totally freaking out somethings wrong with my pregnancy so basically I’m 5 weeks postpartum and I took a cheap test about two weeks ago I thought it was my old hormones so I got bloods done when my daughter was 4 weeks 3 days and the hormones should be out my body I got the results off my doctor and he said I’m pregnant with a new pregnancy and he knows this to how high my levels was I also took a lot of other cheap test all positive and two clear blue that came up pregnant but yesterday and tonight I’ve took clear blue digitals and both came up not pregnant obviously yesterday and tonight ended in sobbing because I just want to know what’s going on it was unexpected the pregnancy as we used protection me and my husband but we was so happy because every baby is a blessing but now I’m scared something is wrong please be nice I just want someone else’s opinion or similar experience

Also sorry for rambling and if it doesn’t make sense