Hi Nikki
Welcome to the group, although I'm sure you'd rather not be here.
A 1cm clot is really small, so that's positive. Your doing the best thing by putting yourself on bedrest. I am pretty sure that's what helped me throughout my bleeding. Laying on your left side and drinking plenty also helps quite a bit.
Not sure about your pains and if they could have been possibly sch related, although I can say I suffered bad period like cramps during my bleed that came and went. This is because if you have an sch that's bleedibg it causes irritation to the uterus, which in turn contracts to try to expel the irritant (blood)
How many weeks pregnant are you? The size of your clot in relation to your baby is helpful indicator too I hear, as If your baby is bigger than the clot, that's a good thing.
Mine was the same length of my baby at 12.5 weeks, and it grew a bit more to 7cm not long after. But all is going well at nearly 24 weeks, so hang on in there