I haven't heard of it but wanted to give you big . I had a recurring SCH when pregnant with dd1 (which resulted in labour at 33w 3d) but my bleeds were mostly fairly minor and I never took anything for them, except rest of course.
I would think tho that it is in a class of drug tho that under 'normal' circumstances u wouldnt take while pregnant but if something is wrong the benefits outweigh the possible risks. Definitely ask more questions of your Dr or get another opinion though if you're concerned, which would be totally understandable! I hope the SCH resolves soon and causes no more issues.