Is it Early Pregnancy?

Hello mommies! I am new here. I feel like I need to get this out of my chest. I am very worried and been having anxiety attacks lately. Last period was Aug 28 and I missed it on Sept 28 which was suppose to be my next due date. Took an hpt on Oct 1 and it came out positive, took another one on Oct 3 and still positive but when we went for a transvaginal ultrasound on Oct 4 (this is 5 days after my missed period) nothing was seen even a gestational sac. Today I am 21days late and is having some pregnancy symptoms like sore breasts, nausea and vomiting, food aversions and mild cramps that only lasts for few seconds to few minutes. No spotting at all. Did we do the ultrasound too early? By the way I took another hpt yesterday afternoon (wanted to try na hindi first morning urine and see if it differs) and it still came positive.