Cryptic pregnancy?

Hey guys,

I was coming forth for some advice from those who went through or know someone that went through a cryptic pregnancy.

My last period was on the 15th of September. I have taken multiple upon multiple tests a few came back as positive and some negative. I went to the doctors which a blood test came back negative. I have been gaining weight recently but no baby bump. I am not really stressed out enough to lose my period.

Would you say this could be a cryptic pregnancy or something else?

Please help!!!