I have gone to work today and forgotten my breakfast and lunch will I have to stock up on Dinner when I get home or just eat as normal.

Also will this matter if I do it a lot.

I wouldn't "stock up" as in try to make up for lost time at dinner. Eat until you are satisfied, but don't stuff yourself or eat all your carbs for the day in one sitting.
Will it matter if you do this a lot? Yes. When your body isn't getting food on a regular basis (at least every 5 or 6 hours), it reacts as if food were scarce and a famine is going on and compensates by lowering your metabolism to help you survive the food shortage which will make it more difficult for you to lose weight.
Skipping meals once in a while isn't going to cause you a problem, doing it several times a week most likely will.
How about planning ahead and keeping some low carb friendly foods at work for those occasions where you do forget such as canned protein shakes or cans of tuna and some packets of mayonnaise like you get at fast food chains? At least that way if you do forget, you'll at least have something you can eat until you get home.

OK thanks for replying

It's because I am really lazy and find it a chore to make something for breakfast as I start early and want to spend as much time with my family before I go to work.

Where I used to take sandwiches or make a big pot of pasta for lunch and take cereal for brekkie.

We don't have a cooker at work or I'd have eggs for breakfast which is not a problem as I like them but lunch is difficult and I don't miss my lunch as I am really busy I don't actually stock up when I get home because I've missed lunch. I'm just stuck already on what to bring for meals mduring the day.

I often don't have time or energy to cook either, but not eating breakfast and lunch just isn't an option!

Here are some ideas:
Hard boiled eggs and cheese
Meat and cheese roll ups (I like turkey rolled up in cheese with some mayo, or salami, ham, etc.)
If you have a fridge at work, prepare some tuna, chicken, or egg salad
Buy precut washed veggies (like celery sticks, broccoli, and cauliflower) and eat with dip or make a salad
Bring dinner leftovers and microwave

In a bind, LC shakes and bars are better than no food at all, in my opinion. There are also tons of suggestions posted on this board. If you do a search for quick tips or lunch ideas or just scroll around I'm sure you'll find some good ideas! Good luck.

Here's some more suggestions:

Cook a crustless quiche on the weekend and then freeze it in single-portion sizes (check out Donald's deep dish pizza quiche in the recipes forum...excellent for this!). Grab one on the way out the door and reheat in the microwave when you get to work. Leftovers work well for this as well...either breakfast and/or lunch. Canned tuna and chicken are always quick to grab. Not sure if your workplace has a refrigerator, but you can keep a jar of mayo there to mix with the chicken or tuna.
Check out the recipes forum. There are a lot of ideas there for foods that can be prepared ahead and quickly reheated when you are short on time.