Question on the Walmart .88 tests

Cassidy • 24 years old. 4 years married. 3 year old son & pregnant with a baby girl 💙💕
So I took a Walmart .88 pregnancy test a few minutes ago and after 3 minutes there was the faintest line but it was still there. Well as time went on, the line started to get darker. Still faint but way more visible. Since it didn't get darker until after the time limit, is that still valid or would I consider that an Evap ? Even though the line was there at 3 minutes, just fainter.