well, depending on your definitin of lots, it could be a concern.
your hosting plan should make it very clear how much space you have available to you. WordPress doesn't require very much at all, and neither do the small pics you're using, but that doesn't mean anything without having some idea of how much is available to you.
the best way to look at this is to work out how long you've been blogging, and then see how much space all the pictures you've currently posted are taking up. If you have them on your hard drive, this'll be relatively easy.
from that you can work out how long you can keep blogging at your current rate of consumption until you run out of whatever's been allocated for you.
... or we can give you a comfort estimate based on your hosting plan details. (I mean the breakdown of what you get, don't do something like post your whole welcome email with your password or anything).