Ttc for a year

Okay ladies, please help me, and be kind. I have been ttc for the last year with my fiancee and it has been tough, i have had symptoms since the week after my last pperiod which was aug 14-19 th and i was supposed to start my period this month on the 17th but I started bleeding on the 16th and it only lasted for 3 days, i have been spotting brown ever since so I suspect implantion bleeding. I have taken a test today and It was negative? Am I doing this wrong or not waiting long enough. I am going stir crazy I just wanna be pregnant. Also, it can't be a light period because there is no way I only bleed for 3 days when all my periods are frequently heavy and last for 6-7 days. I just wanna have a baby so fingers crossed it will be positive in a couple days.