I've Noticed Over The Last Maybe 6 Months Or So

I've noticed over the last maybe 6 months or so that when I'm speaking, sometimes I'll run out of air before I get to the end of my sentence. Maybe I'm not taking as deep a breath as I have in the past, not sure what's different but It's like I get to the end and I either squeak out the last word or so, or I have to purposely take a breath to finish. This occurs when I'm just sitting and talking on the phone or in a room-no exertion of energy. I'm overweight but don't really have issues walking and talking or getting somewhere without having to stop. This has just seemed weird to me. Any ideas? White female, 58 yrs, past smoker (in my 30's) no history of heart or lung issues. Meds: cholesterol, low dose blood pressure