small white worms????

Would anyone know what kind of parasite this sounds like. My toddler has been passing small round but flat in shape things that look slightly hard, almost like a shell of some sort. Today I saw more of these brown, round flat shell looking things with a white thing poking out of one. I got some tweezers and plucked out the white thing and it was a small white worm about an 1/4 of an inch long. I got some more of the shells (or eggs...not sure exactly what it is) and found more small white worms in each one that I cut opened. What the heck does my 2 year old have??? At first I was thinking pinworms but the eggs are microscopic......right? I have heard that you can see some types of Tapeworm eggs and they can be in a semi--hard-like shell.....but as hatchlings, do they appear almost like a small round worm? I have searched all over the net and cannot find anything that fits what I saw. Tweet