I somehow did not pay much attention to the unstable cycle, until I began to have an active sex life. In this regard, many thoughts began on the account of "am I not pregnant?", Because the delays sometimes reached 2 weeks. I solved this problem with OK. Now the cycle has stabilized, and I am calm that now I know for sure that pregnancy will not occur if you drink pills correctly.
My cycle ranges from 23 to 40 days. I understand you perfectly, but in the last cycle I simply could not understand from what moment should I start to panic that I was pregnant. And I didn't. This is treated with oral contraceptives, but finding the right one is difficult. Personally, I survived for two months. Even if it was a clear cycle of 24 days, nausea and dizziness 24/7 for 60 days is still worse. My advice to you - go to a paid gynecologist. If you can somehow live with a cycle of 40 days, then with all sorts of complications that subsequently appear - not very much.
Consult a gynecologist-endocrinologist, perhaps several. Gynecology is not the most developed area of medicine, including in terms of determining what the norm is, so it is better to demand a reasoned scientifically grounded opinion from the doctor, especially if he starts shouting "guard! You have not 28 days!"
If you avoid pregnancy, even with the most stable cycle, remember that interrupted intercourse and "counting by day" are not methods of contraception at all.
If you are planning a pregnancy, be sure to go to the doctor, use ovulation tests and be guided by ovulation.
To avoid panic in case of "delays", calculate the duration of the cycle for the longest option that you had (or the average closer to the longest), and learn to do pregnancy tests without panic.
To make it easier for yourself to plan things that are inconvenient to do during your period, try alternative hygiene products, such as a menstrual cup, which you can bathe with and does not need to change often. If during menstruation it is not blood that interferes, but severe pain, be sure to go to the doctor.