Does this seem like a chemical?

Last night was the strongest positives I’ve gotten since I started getting faint positives at about 9DPO. This morning I had a temperature drop and some light brown colored spotting, and the lines were practically nonexistent although I did a test with water to compare and that one was completely blank. I just did another round with two tests in urine and one in water and again I am getting a very faint line and the one I dipped in water doesn’t have anything, but the tests from right now are slightly darker than the ones from this morning.