Why is this happening?

It is because if you started any discussion you will not see increasing your post but when you reply to others discussion you will directly credit that starting discussion post with this one, I was either confused with this thing most ofently but now I noticed that this is just because of this thing. This is the only fact I see why you see your two post increasing when you do. Another fact will be a glitch sometimes myLot do some childish stuff and I was suffered from many like this. It will be automatically come to the normal posts if you haven't post and discussion up till yet! So let see what will going to happen. Have a good day! Happy earnings.

If you start a discussion your total post count won't take it into account. But after you've replied to another discussion, e.g. you reply to others, then you'll see your post count increase by two. I believe this is normal; don't be freaked out by such technical glitches. If you really feel uncomfortable about it then just contact the admin. I'm sure they'll be more than happy to help.

hi anshnav, dont worry , its natural i myself have witnessed this, so just enjoy and keep posting, believe me there is nothing to worry.