Hello,
Often these types of changes to the menstrual cycle have no known or identifiable cause. If it persists, I'd suggest an evaluation for irregular bleeding that would include a pelvic exam, thyroid hormone level, pelvic ultrasound and office hysteroscopy. There are other ways to approach this, but the aforementioned is one.
Best regards,
Dr. Downing
I meant to say hormonal imbalance also this month I noticed I had no PMS symptoms like I often get. I am trying to get pregnant but with this irregularity its not working? Should I have further testing? What types of tests?