Late and read Negative.. What it is it??

Kassandra
Hello everyone I'm a little confused and need some advice to clarify
​First of all I am officially 2 weeks late from my period as of today. I was irregular before but as of getting surgery done to remove a cyst growing on my left Fallopian tube, I have become like clock work. Different month but same day. I took a home preg test about 3days after my expected period date.
​I am 20 years old, been with my other half for 6 years and been having unprotected for 1 1/2 yrs now.
​okay as for dates my period was due on the 20 of March took HPT on 23 of March and today is the 31 of March  making me 12 days late. 
​I appreciate all the advice you leave me.
​Oh and btw after surgery dr saidy tubes were unscarred and functioning normally.
​Thank You!