When to test

So, for my first 2 months off birth control I had 28 day cycles, then they lengthened. Last month was 34, the month before was 35. Glow has my projected period set to 32 days this month. However, I imagine it's going to be more like 34 or 35 as I believe that is my new cycle length. So glow is telling me to start testing tomorrow which is 3 days before it thinks my period will come but at least 5 days before I think it's due. I have one previous frer left and I don't want to waste it.... I had been thinking of testing on Valentine's day which would be 2 days early for glow but 4 days early from what I think.....

Should I wait?

Should I go buy a few dollar store tests to feed my need to poas?

Should I throw caution to the wind and test with the expensive test?

Lol.... I hate bfns so much, even more so when they are on the expensive tests.