Hello, babydoll! I'm not a medical professional, just the parent of a kid with diabetes. Different insulins have different peaks, they take different amounts of time to take effect, and they wear off at different rates. I suspect that is what you're seeing.
Apidra takes effect in 10 - 15 minutes, peaks in 30 - 60 minutes, and is gone within 4 hours. Levemir takes effect in 3 - 6 hours, peaks in 6 - 15 hours, and is gone within 18 - 24 hours.