Luteal phase length

I've been ttc for 3 cycles now. My cycle is typically 34 days. I've been tracking my cycle and I'm noticing that my luteal phase is not long enough. It has been 11, 5, and 7 days the past 3 cycles. I've been under a lot of stress, so I'm not sure it I should be worried yet. How long are your luteal phases on average, ladies?