Ammonia smell early pregnancy sign? With bfn

Hi all. This is probably tmi but what else is this app for eh? The past few days my underwear has had a noticeable ammonia smell, which I've experienced before but that has been few and far between. My discharge has been milky/watery and there's been a medium-high amount of it depending on the day. I'm 1 day late for AF with a BFN this morning and yesterday. I don't have any itching or discomfort or weird colored discharge so I don't think it's an infection.

Could it be I'm pregnant but it's just too early? I've had some cramping on and off for a week which I thought was AF but she isn't here yet. I don't have any other pregnancy symptoms.