Taz,
You poor love. It does sound to me also like your mucous plug. I really hate that phrase it sounds like.... I dunno it just doesn't sound right!

If you found it in your bed this could be why it's a bit gristly- if it had dried out some before you found it... I would report it to your care provider but would feel quite confident that it is "THE PLUG". This can happen some time before labour begins...

As for that itching... Have you had some bloods done? If so and all is well then I would return to your care provider to review the script. If it is decided it is safe in pregnancy then I would take it. What we worry about is that some antihistimine meds can cause the baby to have some respiratory difficulties if the baby is born soon after you take a dose. You do need to have the script looked at and the decision made weather or not for you to take it in light of your "plug" find.

In the mean time if you have some chammomile tea bags these are really wonderful for relieving itch. Have a nice warm bath (too hot can irritate the skin more) and add the tea that has been well "steeped" as you would make a cuppa but use about 6 teabags for a bath tub...

I hope things improve soon...