"If they're growing, you're golden." That's what I say.

I did the same on my first grow. I just threw shit together from local convenient stores and got some shultz plant food... I started on that and some other household gardening nutrients that I had laying around. I switched over to the gh 3part about three weeks into veg and they grew fine, I was amazed to watch the plant shoot up when i ran the 35 dollar dwc setup properly. It was fun to grow for sure. You might wind up paying more than you originally bargained for though; It's easy to buy little things here and there that build up the grand total.
good luck.