Advice on a membrane sweep.?

Im due to have a sweep tomorrow, the day before my due date. How "natural" are these. Im worried that it might cause problems later in labour, much thesame as being induced can. Im hoping to do labour as a natural water birth with no drugs, and am slightly worried that having a sweep will encourage other things to go wrong, forcing me to have an epidural/c-section etc. Im a little green as to all the technicalities as this is my first, and would welcome all advice. Thank you