You likely already saw my comprehensive hCG Dosage Guide (and if not, please check it out!).
In there I discuss an aspect that I think probably applies to your case here. Since it’s your first day of VLCD, yes hunger is very common – especially after loading. My dosage article explains in more detail that when you eat a lot like during loading (unless you clean load which you can consider for next time!), invariably you usually end up eating a lot of carbs and sugar – this elevates the ghrelin hormone soon after which is responsible for growling tummies/hunger pangs. So this is likely what you are experiencing. Even when on the right dose of hCG, especially if you loaded the traditional way eating whatever suits your fancy, you will likely feel a fair amount of hunger at various points throughout the day the first few days before you start to adjust.
If you were on a very high dosage, say 250iu and feeling this, I might consider dropping it right away as that dosing is typically too high for most people, but since you are already starting on a dosage that is generally pretty good for a majority, I would just wait it out a few days in this case and see how you are feeling at the end of VLCD 3.