Question About THC Urine Test Strip

OK I took the advice from people on this site and got myself a home test kit. This was not easy living in Canada as it is not sold in Wal-Mart or pharmacies. I had to find a head shop that had one. The one I found was Purple Sticky Brand 1 Panel Test Kit THC. The test calls for two rose-pink bands for a negative. One in the control zone and one in the test zone. I tested my first stinky urine of the day. The result was a sold dark line in the control zone and a very faint but visible line in the test zone. What does this mean? Does the faint line get stronger when you have less THC and it's by-product in your system? The test instructions said nothing about a very faint line. Any assistance would be appreciated.