Ovulating right before period

So I'm on CD 27 and all day today I've had clear stretchy discharge and I know that can be a sign of ovulation. I used opk from 2 days after my period to about CD 21 (never got a positive and I did them twice a day) and then I stopped bc I figured I must have missed my LH surge somewhere. Is it possible to ovulate this late in your cycle? I know it's a stupid question but this was my very first month using opk test so I'm not sure about any of this.. Maybe it's just the discharge before my period starts bc the app says my period is due tomorrow even though it usually doesn't show up til the 28th/29th..