You can file for a divorce in South Carolina even if you are pregnant. However, in South Carolina there is a one year waiting period for a divorce after you separate unless you have grounds for an at fault divorce. You can go to court and obtain a temporary order of separation if there are no at fault grounds. The link below lists the grounds for divorce in South Carolina.
Most likely, yes. I don't know SC law, nor do I practice there, but your pregnancy shouldn't be a bar to the granting of a divorce. The court may (or may not) actually process the divorce before you have your second child and an attorney worth his law degree could find easy and legitimate ways to make this happen.
The divorce decree would likely note that you are pregnant and that he is (or isn't) the presumed father. Any child born during a marriage (or shortly thereafter in a divorce) is presumed to be the child of the husband.
The above is not intended as legal advice for your specific situation or intended to create an attorney-client relationship. Talk to a lawyer for advice tailored to your specific needs.
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