A lot of pharmacies have blood pressure machines that you can use for free, so you could check your blood pressure there on a few occasions and see if it's consistently high.
As for treatment, the DASH diet
has been shown to reduce blood pressure. It basically emphasizes fruits and vegetables. Vegetarians tend to have lower rates of hypertension
, which is probably due to a number of factors.
If you do have hypertension, it is probably best to see the doctor anyway. Sure, you can make dietary changes on your own and check your progress at the drug store or with a home monitor. But doctors know how to check for other problems that can go along with hypertension, and your doctor may even want to start you on medications, depending on how high your blood pressure is. Good luck, and I hope everything turns out okay.