Silly Sausage - it really won't be long before people start to notice. Actually, some probably already have but don't want to say anything either because they don't know you well enough or they're not sure. You may also find over time that people may say to you 'you look really well' because they know something is different but can't put their finger on it (often men who just don't really notice as much !).
Also, are you wearing clothes that fit properly ? That's the other thing that masks weight loss. Even if you've lost a lot of weight and your clothes are loose, if you're wearing stuff that's way too big, it is much less noticeable. So if you can, ditch your big clothes and start wearing stuff a bit more fitted. I guarantee people will start to notice soon though. They won't be able to miss it.
Good luck !