I am wondering the same thing. I believe I lost my plug Sunday but not 100% sure but my stomach has been hard constantly but no contractions. I go to the doctor tomorrow so I'm going to ask. I'll let you know!
It means that your pregnant..... Lol. I've been losing my mucus plug for a week and my stomach is hard too, because the baby is growing and there isn't much room in there anymore that's all that means.
Keep in mind your mucus plug is the size of a fist.. It would be very noticeable if you lost it all at once.. Most everyone loses it slowly.