Hi Jannie,
Sorry to hear you had this issue. We haven't heard of the precise scenario you described but anytime undue pressure is placed on your pelvic muscles, there is a chance that you will have leakage because the Softcup is dislodged. Coughing or sneezing can cause this.
Otherwise, leakage usually occurs for one of two reasons. First, because the Cup isn’t covering the cervix properly. If this is the case, leakage will start right away. If the cup leaks only after you have worn it for a while, it may be getting too full and needs to be changed more often. By the way, the cup will never appear "full" when removed from the vagina. When in place, it is partially collapsed and cannot hold as much as it can when it is fully open (not in the vagina). Although the cup is designed for 12-hour usage, some women can't get the full benefit of this. What we usually tell Softcup users is that it can be worn roughly twice as long as a tampon. Since flow can vary day to day, how long you wear Softcup can vary too. I hope this helps! Please let us know if you have any other questions.