First missed period after 2 years

I got Liletta inserted 2 years ago and have had a pretty consistent period since. DH left for deployment November 4th, so we said our “goodbyes” pretty much the whole 3 days prior. I had an extremely light period for November (only about 3 days long with barely there bleeding), an even shorter one for December (about one day with light spotting) and so far I’m 10 days late for January. I wouldn’t normally be worried except when I felt for my strings, I felt them almost immediately after inserting my finger. (It used to take some feeling around before, I have short fingers) and now even though I’ve been eating healthy and working out, my pants are getting harder to button up. Any thoughts?