Ay, mama, that's a question you really need to ask your OB-GYN about ASAP, especially kasi 38 weeks ka na! Discharge changes later in pregnancy can mean different things, and only your doctor can check properly and tell you kung normal lang or kailangan ng action.
A few of us mums have had different experiences at that stage, kaya talaga, better safe than sorry na lang, text or call your clinic agad, or if it feels urgent, go to the hospital. Take care!