Am I about to get fired?

I work at a grocery store. I forgot to look under the buggy for items, and the security guard asked if I did. I (ashamedly) said "no! can you get them for me?" basically, after wards I got in trouble for that. That was at the beginning of my shift. They told me to be more careful. I did well afterward. Today I checked my balance and I got paid maybe 30, 40 dollars more than I think I should have. Maybe I'm wrong, and I didn't get paid for the week prior, because the week prior it seemed as though I got paid less than I should have. Did they pay me more this paycheck because they're going to fire me? Lol, I know it sounds stupid, but I'm nervous to go in now. I have work tomorrow, and I haven't been called or anything to not come or whatever. So.... am I?