I just finished sealing my asphalt driveway yesterday morning. Temps have been in the mid 90's and humid, and there's been no rain. As of this question, it's been about 36 hours since I sealed the driveway. I'm starting to see multiple stains like the picture below coming through the sealant. I think they were there before, but I thought they were just where the asphalt had worn more excessively. I'm not really concerned about looks. What is this and should I be concerned about it?