Dizziness while exercising

This is my first month ttc. First month using glow and so my so and I are bding every day not to take a chance and miss my o. Long story short, I am a runner. I usually do a 10k every week. Tonight I went for a run, only 2 miles, and got really bad heartburn and when I finished I literally was staggering like a drunk person. I couldn't walk a straight line to save my life. My question is this: For those of you who have conceived before and regularly exercise did you experience these symptoms or ones like it before your bfp?