How will i know that i am ovulating when a circle lasted for 26 days it isregular or irregular?

Your question is not clear but I will try to answer. Regular cycle is often a cycle with ovulation. If cycle is 26 days, day 13th is the expected day of ovulation counting from the first day of your period. Cycle length between 21 to 35 days is normal.

Normal ovulation (i.e.the release of an egg from an ovary in a normal regular menstrual cycle)is believed to usually occur about day14 before onset of normal regular menstrual bleeding. If you have a regular 26 d cycle, ovulation would probably occur about d 12. If your cycles are irregular, it would be best to consult a Gyn Endocrinologist to find out why and also determine when / if you ovulate