Enormous hugs MrsE - as Spinning rightly says, early pregnancy is such a worrying time. So much so (and please don't judge me for saying this) that I'm almost dreading my next BFP (assuming of course I get there). This is ridiculous of course, as I desperately want children (and more than one at that) but with two early losses under my belt I just know that I won't be able to relax properly / think of anything else until the 12 week scan is done and dusted.
If I were you, I'd enjoy your bath, take it easy tomorrow and if you're still worried on Monday, try and get scanned at an EPU. I'm conscious that they're unlikely to see very much at present, but they should at least be able to tell you that your bean's in the right place and is developing as normal. That having been said, it's really positive that you don't have any bleeding, and cramping as the uterus expands in early pregnancy really is quite normal. Keeping everything crossed for you.