I was just wondering whether im supposed to check by pressing my fingers on their tummy every once in a while?
No.
And personally I have never done that because if there is an egg, you can easily break it.
An egg is always very visable just by looking at your birds, side-on. Sometimes they look a bit swollen, other times you can clearly see the egg shape.
You are better to monitor your birds visually for signs of trouble, monitor whether they have a bump or swelling, if they are lethargic, if they can´t stand or are flailing, loss of balance etc.
Here is an article about problems that can potencially arise during egg laying, and what to watch out for;
edit; I forgot to ask if your birds are flighted? And if they get time to fly about in the room and strengthen muscles? That will help them during the laying process. An unflighted/clipped bird is weaker and is more likely to have trouble with eggs.
Another thing is to have veggies available for them (or pellets) so they have access to vitamins