Real positive, or HCG trigger?

This cycle, I had an u/s on day 11 showing a 19mm follicle. I triggered cycle day 12 at 9:00 p.m, this was October 4th. On Tuesday (10/12) I tested with a dollor store tree test to see if the trigger left my system, and it was negative. Last night I tested with a one step test, and was positive. But it was so light I thought I was seeing things. I tested again a few hours later with first response early detection, same result. I took another first response this morning, and a positive line came up but lighter than last nights. What is happening here? Am I to ume this is trigger?