This might be the answer.    On your Options you can check the box 'email replies to my posts' and I expect that 2 people have just carried on the thread by clicking on your post but not actually in direct reply to your post. 

On taking a second look, one of them IS in reply to you but the other is a reply to the OP.

Oo er thanks Sally, roll on this afternoon when daughter is back and can sort it.:)

Hi when you post a reply at the bottom after the message text box and next to the post button is a box if you click it it sends email notifications of replies.

Hope that helps.

Sue

Sorry just come back on line and find it has all ready been answered.