Hesitation On Start-Up

[2001GTPEWTER]

I'm having a little hesitation when I key the ignition on my 2001 GT, these cars are hard to check without a lift so I wonder if anyone has any ideas if its anything I should worry about. The cars' got 90,000 miles on it, it shifts great, handles fine (except for the occasional squeek in the back when I go over a sharp bump or imperfection in the pavement), but otherwise I can't see why it would kinda half shit-out on me when I first start it up on a warm morning...or am I just a moron whose mind was somewhere else and he did'nt keep the key turned long enough....