Chemical pregnancy.

Jaimi • Jaimi. 28 years old. Herb is DH. 16 month old daughter Evelyn. Pregnant with #2. 9/23/17
I tested positive (very faint) 2-3 days ago. I've tested every morning since to make sure the line was getting darker. They've now disappeared. I'm absolutely devastated. We had a twin miscarriage 9 months ago too. 
​That being said should I call my doctor to run tests or just let nature run it's course?