Stupid question, hopefully someone knows the answer

Hey ladies, I took a test last night I received a vvf BFP result. I was over the moon happy this morning I took another test and it was fainter (almost couldn’t see the result)... I then read the instructions for some dumb reason I thought when you dip the pregnancy test in a urine cup it needs to be dipped for 15 seconds ( I think I was going off what my Digital OPKs said) anyways holding the stick in the urine too long by 10 seconds wouldn’t give me a false positive would it?

They were both first response tests, is there a reason also at night one is way darker then the one I took this morning?

I appreciate any answers ladies sorry for the long message