Great suggestion Berry1 about progesterone.

I would also get your DH sperm tested as I know from experience working as a midwife that some women who have multiple losses (especially early ones) can be from sperm morphology. As they are still able to fertilise the egg but then as they are not perfect sperm they embryo can not develop properly and a m/c (either sponatenous or missed) occurs. There are many number of things that can cause m/c and many are unknown but after one or two occurs I would strongly recommend some simple tests like blood tests and a sperm anayasis to see if it sheads some light. GL you have another baby soon.