Sewing machine issues:(

[lemon-bonbon.livejournal.com]

Sewing machine issues:(
Just today I am having an issue with my machine, it's sewing the stitches the wrong side up, whilst using the zig zag stitch I noticed that the zig zag was actually on the wrong side of the fabric, on the back side, instead of on the top! I tried other stitches and it's the same thing. Also every so often a stitch is really loose too.
The only thing I did differently to the machine is change the needle, any idea what has happened to it?

If anyone can tell me, that would be great!