You certainly CAN be the father. The pull out method is very unreliable and worse, you wiped off and went back in. You didn't, can't, clean out any semen (containing sperm) in your urethra. Just inserting your penis can squeeze that semen into her vagina.
There is no way to know exactly when she ovulated - after the fact. Besides, sperm can survive for about 5 days as you know.
Meth may make the other guy impotent but it won't make him sterile.
You'll need a DNA test to determine paternity.