Could I be pregnant?

As you can see by the photo, my so and I were not necessarily trying this month. Well I’m currently 4 days late for my period, I have a sinus infection, and glow changed my dpo from 11dpo to 10dpo. I haven’t had any of my normal pms symptoms except very light on and off cramps since the day my period was suppose to start. I’m normally a 28-29 day person. So 99.99% of the time I am never late. Pregnancy test on the day of my missed period was very very very light and then the next day was negative. I checked my cervix this morning and it has finally dropped a little. I will check it again later on. Any advice or insight to what’s going on would be greatly appreciated.