Thanks for you query.
I read your query and I understand your concerns.
Following is my reply:
1) It is not possible to get pregnant with oral sex
and hence no need to worry.
2) Cycles variation you are experiencing are due to lack of sleep and stress
you have mentioned.
I hope I answered your query. I will be available for any follow up query you have.
Dr. Mahesh Koregol
IVF & Infertility