How to tell the difference? TMI post no pic

Sabrina🌸 • 🤵👰7/25/15 👧🏼12/6/13 👼2/21/15 👦3/26/16 👧6/27/18 I`m 26 and have 3 beautiful babies! Due with #4 September 2020
So my husband and I had sex last night then went to sleep.. this morning when I went to the bathroom and wiped it looked like I had ewcm, but I don't know if that's what it was or if it was leftovers from sex. How do you tell the difference