4 days late!

Kennedy ā€¢ Married to my soulmate since 7.4.2020!šŸ’šŸ’ž We have a 4 year old son, who took a year and a half to conceive! We are expecting baby girl March 11th 2021 after 2 1/2 years of ttc with fertility treatments šŸ’–
So I am 4 days late for AF and I usually have signs of severe cramping and whatnot 3-5 before I am due. And I have 0 signs. 3 negative hpts and Im never late unless its 1-2 days. February was a short month so I get glow could be 1-2 days off but that would still make me 2 days late. Is it possible I am pregnant but I dont have enough hcg to show on a test? Ive heard of this happening before I just dont want to waste money going to the doctor when its nothing.