I FAITHFULLY Start My Period Every Month Between The 24th-26th

I FAITHFULLY start my period every month between the 24th-26th no matter what ...I did last month and then randomly bled for 1 day about a week or 2 after I ended my normal period. Now this month I havent gotten it yet and ive been wicked sick the past few days worse at night then anything.. Do you think my period is changing or possibly pregnant ? My cervix feels low and soft