Hmm, lendir kuning macam tu biasanya bukan mucus plug lah, mucus plug usually nampak lebih pekat, maybe whitish atau agak berdarah sikit, dan keluar dalam satu ketul besar-besaran. Lendir kuning yang keluar masa kencing tu lebih likely discharge biasa je, especially if you had diarrhea tadi (hormones lah kot), tapi since you're noticing something different from before, best to just WhatsApp your gynae or clinic to describe it and get peace of mind, okay? Jangan stress, first pregnancies memang banyak pelik-pelik yang bikin kita paranoid, tapi better safe than sorry!