Looking at your profile, there are 48 submissions counting this one. Over 18 days, that's not unreasonable considering that they often are receiving upvotes and several have generated meaningful comment threads.
I tend to submit articles in clusters, so I suspect that it is not an uncommon pattern. So long as your submissions are not getting heavily flagged you should be ok. If you find yourself banned, take a few weeks break and work on your comments.
