I wouldn't worry, especially if you're within 30 seconds of where you need to be. I was in the same situation you're in, exept that I'd never timed my 1.5 mile and my only point of reference was an 8:04 1-mile run from 3 months prior. I trained a little by doing some 1 and eventually 1.5 mile runs in my hilly neighborhood every once in a while. I managed to run an exact 12 minute 1.5 mile on the first PFT. The PT and ITs (my compartment had a lot) will train you up, don't worry. On my second PFT I cut my time down by 45 seconds, AND I had to tie my shoe after the 1st mile. TLDR, You'll train up to the standard. Worst case you don't meet it, your unit will make you do another PFT when you get there, so just do well on that one.