Mary, even if the Sea Salt enemas are not resulting in the elimination of more solid waste matter, the water you are expelling is probably loaded with toxins, so you are probably receiving greater benefit from the enemas than you realize.
The soap solution enemas will likely cause a bit more discomfort from cramping than with the salt solution, but will probably also result in a better overall release of waste. In the end, most people tend to agree that the slight amount of additional discomfort is worth it. Your bowels should move every day, especially during pregnancy.
When are you due?
Best wishes for your natural health and that of your baby,