Seeking Advice - Hereford,TX

It could be the beginning of "the change" ;), it could be stress, it could also be that you've been around an "alpha" female, and your cycle is syncing with hers. ((Alphas have nothing to do with personality, just pheromones), and it could also be diet.

Personally I'd call the doctor's office and ask when then want you to come in. Many, if there is no pain/other symptoms, want their patients to wait 3-6 months so that they can track patterns in menstrual shift. Others want you in right away for blood work. But the phone call is free... and it will give you an idea of what your office wants you on the lookout for.

Sounds like Peri-Menopause. This can start happening in your 30's.

Take a pregnancy test, if there's a chance you're pregnant- get that worry out of the way! :-)
Perimenopause can start in your 30s and last until you transition into real menopause in your 50s or even later. My periods started becoming slightly erratic at around 38 years old. Some were late, some early, and for a couple of months, I had what can only be called a "comma", not a "period"... lasted off and on for 7 weeks. My Dr gave me iron, and, eventually, an over-the-counter progesterone cream, which has helped immensely!

Seriously, do not worry about this right now. It sounds perfectly normal- and you just had a checkup, so you really can breathe a sigh of relief (if that pregnancy test is negative!), and enjoy your vacation!

I was so regular that it came between 9 and 9:15 am every 4th Thursday. Around 40 that drastically changed, periods that lasted weeks, very heavy with large clots, severe cramping, dizziness nausea and migraines. The doctor put me on a birth control pill that allowed me to only have four periods a year. All of the problems stopped as soon as I started. Keep track of your periods and symptoms then approach your doctor with facts it will make his/her treatment easier.

Keep the notation on your calendar, go on your vacation and if you still haven't seen a cycle. I would make the appointment to see the doctor about a week or two after you return from your vacation.

Have a good time and don't worry. The body does change.