I am in the TWW for an IVF cycle recently completed. Earlier this year I was pregnant but it ended in miscarriage.
Last time I ordered these Wondfo tests and they worked great, saw line progression as things moved along, etc.:
https://www.amazon.com/gp/product/B07GZXTRDZ/
This time I ordered what I thought were the same tests but I realize now they are different, notable the others are marked "early" response. On top of that the test package was sketchy, no box just in zippered baggie but they are not expired:
https://www.amazon.com/gp/product/B0002YIQEQ
I got the barest squinter both yesterday (12DPO) and today (13DPO); beta is Tuesday. I was disappointed that the line got no darker so I went back through my text photographs (bc last time I texted the pos test to DH). My memory was not wrong; the line was much darker at the same point.
My question is do you see variation in Wondfo tests? I know a line is a line and this is 100% out of my control but help me calm my fears.