Negative Frer, positive cheapies?

This morning I took an 88 cent Walmart test and a frer with fmu. Walmart cheapie showed a clear line around the 10 minute mark, frer looked like it had a colorless indent line. Took another cheapie from dollar general this afternoon and it showed a vfl, but this time within the time frame. I had some spotting this morning which I'm hoping was implantation and not a chemical. Currently 11 dpo. Anyone ever had positives with the cheapie but negative on frer? Isn't frer supposed to be more sensitive?

Of course I know no one here can give me real answers and I just have to test in a few days, I'm just going crazy over here 😩