Longer cycles

Since TTC my cycles have gotten longer by at least a week. The last three months they've gotten much longer. normal for me is 5 week cycle give or take a few days but I had a 7 week cycle two months ago and a 6 week one last month. this month is looking to be long too as i'm on week 4 but don't think i've ovulated yet. I caught ovulation last month and got my period exactly two weeks later. Anyone else find their cycles got longer when TTC? i'm wondering if i'm either getting pregnant but it doesn't implant and it's messing up my cycles or if it's just stress and impatience?