Yes, you now have a veset kavua for a 26-day interval. if you have three consecutive cycles without bleeding on day 26, you will stop observing that veset. But as long as you do not establish a different veset kavua, if you later do have bleeding on day 26, then the veset kavua is immediately re-activated. That interval returns to being your only onat veset (unless or until there is a change).
It is very common for women’s cycles to change in their early to mid forties. Often, the cycle shortens gradually over time and then slowly lengthens until it stops altogether. The process often takes years.
Since this is a normal phenomenon, taking action is not indicated on a medical level unless your physician advises it. Experientially, it can be challenging to live with a shorter cycle. Some women seek medical intervention for this reason, which is often effective. Others pursue alternative treatments or adjust their diets to try to lengthen their cycles. Others just wait it out and make their best effort to adjust.
It is particularly important at this stage to review the laws of stains (as by reading our article here). You and your husband might also wish to consider if there are stringencies you have practiced which might not be as well suited to a shorter cycle and seek advice with any questions.
We wish you good health as you go through this transition.