Spotting

I'm currently 6weeks pregnant and a few friends and i went hiking. Well we took the wrong path and what should have been a 3mile hike then turned into an 8 mile hike. I have been spotting intermittently.. it's pink and when i wipe it's pink as well. I called the doctor and they told me it's normal to spot after something strenuous.

Has any one experience this before? I have miscarried in the past and i feel very freaked out. I can help but feel worried even though the dr says it's okay. Should i wait it out this evening and call the dr back? Or should i go to thé ER?

Thanks