AF due 12/14

Kari • I`m 33, newly married and mother to adopted 12 year old son TTC for second child but first pregnancy.
My period is due 12/14 but Glow all of a sudden changed it to 12/12 but my other app that I have used longer says 12/14. I took a pregnancy test yesterday because it was my husband's birthday and I was hoping to surprise him but it was a bfn. Dying to test again especially since my boobs seem to be getting bigger and sore. I told myself to wait until Saturday! Hoping my my bfp then!