The answer to your question is basically depending on if you decide to:
- allow all other worlds to have totally different physical laws then ours, different combination of them, maybe no laws at all
- all other worlds must obey the same exact physical laws
In the case of 1. the answer to your question is yes, all of them exist. In this case all kinds of combinations would be existing, since there is no limit for example on the amount of energy, speed of expansion etc. The size of these parallel worlds would not be limited either.
In the case of 2. the answer would not be so simple. In this case the number of parallel worlds would still be infinite. But all these infinite worlds would just be versions of our current one. All of the infinite ones would start with a big bang like ours, just they would end up differently, depending on little changes in the starting setups, like the allocation of energy, particles differently allocated, (though the amount of energy would be the same as our world's), but maybe the size of the starting point would be different (where everything is bunched into before starting the big bang), and so the energy of explosion would be different. maybe the era of inflation would be different too, longer/shorter then ours. So this way all those worlds would exist, but maybe the arrangement of the particles/energy would be different in them.
A little background on this to understand the question:
(Imagine a 6D world, where our 3D space would be then extended infinitely in a 4th dim., can call it time. Then we have a infinitely long (both directions) line, with every point of the line having one of our current 3D spaces. So then we have the 4D timeline, and infinitely replicate it on the 5th dim. That looks more like a flat surface filled with our 3D spaces in 2 dimensions now, the 4th and 5th. And then you just replicate this 5D world infinitely into a 6th dim. So then basically you have Our 3D world infinitely expanded in 3 more dimensions. Each coordinate of this 4th,5th, 6th dim system has one 3D world on it. Those are our parallel worlds. Now imagine that the timeline as we imagine it now is not linear, but moving in 3 dimensions, the 4,5,6th. So basically our world is currently in this 3D sytem somewher and as we pass through time, we move on this 3D grid. our timeline describes the possible line through this system based on our starting settings and out laws. Nobody can change it, since that wouldre quire too much energy. But those other worlds on the other spots of this 6D grid are all existing parallelly)