Whenever you have an orgasm.....solo or not........you definately will know if you cum. Your usually wet even before you cum.....and afterwards its just even more. For most women its more of a feeling then anything else. Its a pleasurable feeling that builds up and and then its like a release that leaves you feeling warm and tingly all over

For men its kinda obvious because they ejaculate..... Some women can too I hear.... But not all women do. Its just more wetness after you cum.