I think it was the test that gave you good results, lol.... 300mg is nothing and kicks in like 8 weeks later. So 2 weeks of lowly peaked levels unless you have super good receptors is very unlikely to be the cause of what you saw.
i think i'm hyper receptive, for example, 10 mg of good dbal for one week is enough too fill up my tshirt, when i was 25, 1ml sust e.o.w + 200mg of deca e.w was enough to make me gain a lot of weight and strenght specially on squat. I even remember the very first day i took aas, it was one caps of pantestone, in 1997, three hours after my body was changed, traps, chest, even my face.