No Fermentation.

I made an Austin's Oatmeal Stout on Sat, and pitched a White Labs English Ale yeast. All my temps were in range and sanitization was done to everything touching the wort after boil. It's been three days with no activity. Just took a reading. Gravity is still 1.053 (the same as my SG on Sat.). The one thing I did notice is that it looks like it was starting to form an infection on the top.

I have a US-05 dry packet in the fridge. If I pitch, will it affect the taste of the stout due to it being a differrent yeast strain?

Only things I can think of was maybe lack of aeration or bad yeast or like you mentioned, a possible infection. I'd keep an eye on it for a day or two. I'm sure Revvy will be along soon. He loves these fermentation posts. He's the guru and would be better suited to enlighten you.

You sure its an infection, you said you pretty sure on your sanitation. Could it be the beginnings of the kraussen?

If it's not an infection (finger crossed) I'm thinking to give it one or two more days before re pitching. IF you re-pitch the SAFALE US 05 should not affect the flavor. US05 is a pretty clean yeast strain from what I understand and should let the flavor of the stout stay forward.

I thought it was the beginnings of Krausen, but then I noticed that it started looking greyish in color, and when I took the airlock off to take a reading, it's starting to smell not so pleasant.