You didn't mention specific examples of words you have formed, so I can only answer generically. The answer is, yes and no.
Yes, because English has no formal governing body that dictates what is correct or incorrect. Rather, "correctness" is determined by consensus usage. Although there are dictionaries and grammar books, lexicographers and grammarians are supposed to document common usage, rather than make up arbitrary rules. Furthermore, English has a long tradition of accepting new compound words, stretching all the way back to the days of Beowulf. If your word successfully communicates your intent to the listener, then it has served its purpose. For example, the built-in spellchecker in Mac OS X highlights undoneness as not a word, but I would consider it a perfectly fine word to use (as in "I was uncomfortable with the undoneness of the hamburger"). There is a lot of tolerance for inventiveness, particularly in spoken English.
No, because there are limits to what words people like to use, and those limits are somewhat arbitrary and illogical. Why can someone be disgruntled, but not gruntled? Why is postpone a standard English word, but prepone is only common in Indian English? Why is it antidisestablishmentarianism, but not contraunetablishmentarianism?
There's a whole tag on english.stackexchange.com dedicated to this topic: [is-it-a-word]. That is, unfortunately, the simplest answer I can give.