Had an accident with condom failure 10 days ago, took morning after pill 9 days ago. Now have very sore nipples and spotting. (Nothing at all like a period, looks more brown and only when I wipe) Never had morning after pill before, is this just a side effect? Beginning to panic in case it hasn't worked

There's really no way for us to know for sure.

It could be from the pill, it could be pregnancy, nothing is certain. At 10 days it would be too early for pregnancy symptoms, so it's likely due to the morning after pill. It will throw your schedule off.

Wait until your next period is due, but realize that that period may also be off. If you don't get that period, try a pregnancy test.

The morning after pill only decreases the chances of pregnancy, it doesn't completely eliminate them, so pregnancy is still a possibility. Now you just have to wait and see.