Glow giving wrong ovulation dates?

So my husband and I have been trying to concieve now for 9 months and it's our first time so we are very new to all this. So I'd say for at least the first 5 months we centered our activity in the nice green week glow gave me based on my cycle. Well after enough bfns I started doubting the accuracy of those time frames so I started taking ovulation tests every now and then. So this cycle, for example, glow has my peak day as this Thursday. I started taking ovulation tests about a week ago every couple days and I never did see a test I'd consider positive but my pink line has completely gone away by this point. I'd say the closest I was to a positive ovulation test was last weekend. Aside from throwing tons of money away on ovulation tests these past few months, I also feel really cheated that glow has been leading me astray by at least a week! Has anyone else noticed this from this app? It's fairly frustrating. Any advice would be appreciated.