Do Not worry about it. The exact same thing happened to me when I took the GMAT for the first time.
Towards the 10th question, I got a tough number properties question that destroyed my confidence. Afterwards, I started missing easy questions (geometry - algebra .. etc)
I'm still surprised how I managed to get 48 on the Q section. All we need is confidence control during the test. Missing one question is ten times better than missing 3 questions in a row, just because we missed the first question of those three.
One more thing, let's make sure we cover every single part of the Quantitative section of the GMAT. I'll try to create a post with the complete list of all GMAT quantitative topics.