Glow changing period date?

So I just went on my period tracking calendar on Glow and clicked where it said "period late" and it pushes my cycle back two days on the calendar.. I'm pretty confused. So was I suppose to start today, or two days from now? I was suspecting pregnancy since my husband and I have been trying for 6 months now, and I haven't had any period symptoms yet but it made me feel a little doubtful 😔