Hi mama2leah - I think this sort of thing is very very common after you have had a baby (I assume you have, or are you pg?) If you are at all concerned or in discomfort, take yourself along to a nice lady gp and explain how things feel so she can check you over and give you the reassurance you need.
33 weeks pregnant means you have at least a stone's worth of pressure pushing down on your pelvic floor at all times. I'm not surprised you are peeing yourself. Not to mention the very short gap between pregnancies. You probably have a pelvic basement rather than floor.
Ask your midwife if you can be referred to the postnatal physiotherapist for some help post partum.
Completely agree with whomovedmychocolate - it took me about 5 months for my body to feel "normal"-ish down there again, so you probably didn't recover from your first pregnancy before you hit it with another one. Have you explained these feelings to your midwife? It may be that you have haemorrhoids (sp), in which case you may be able to get some relief from pessaries etc. Think I have wet myself quite a few times since the birth of my ds, but I am reassured by every mother I know that they were the same!!!!!
I have a crap pelvic floor too. My DD is 13 months and I am 25 weeks preggers. I am doing my pelvic floor exercises as I was really crap last time and paid for it afterward, but it has to be said I am not very good at remembering. Mine aches at times adn I have peed a few times when sneezing. I have worried about it too much and just try to do my exercises when i remember.