No, that's fine. That's how it should be. The only time I've had it spray out on me is when I followed the directions to "shake well". I did that, and opened it and had an amazing yeast fountain/shower. I now shake it up to mix, then ever so gently open and get a small "pssftt". Then, I open it the rest of the way. There's no reason for it to be under pressure, so it sounds like it went just fine for you.
Broken Leg Brewery
Giving beer a leg to stand on since 2006