The morning after pill and ovulation.. help!

So me and my partner are in a long term relationship and have been trying for a baby for 2 years so I am off all contraception.

Anyways I have just started a new job so we have decided to be careful for a little while..

My last period started 27th feb and I have been having cycles around 27-28 days, my app suggested I ovulated on 11th March (cycle day 14). I wasn’t tracking ovulation so don’t know if it was far out. Anyways we dtd on 11th March and got too carried away and he cum in me. I panicked as we were deciding to wait and when I went to the toilet I had a fair amount light blood (I’m guessing this must be ovulation bleeding? Although it’s never happened to me before?)

I took the morning after pill Levonelle on 15th March , 3 days after we dtd, it was the earliest I could get the pill, so was around 72hrs when I took it which I know is the last chance to take it.

Is there a chance I could still be pregnant? I’ve read conflicting info online, some saying the morning after pill doesn’t work if taken after ovulation anyways? Any advice would be great! Thanks