I'm From The Philippines. I'm 18yrs Old Turning 19 This

I'm from the Philippines. I'm 18yrs old turning 19 this october. I really need your help.. Have a irregular period. The last time I've had a period was on July 18 this year. My period didn't come on August and this month of September. I do have a boyfriend, but we both know that we've been safe. And the intercourse happened for only a minute. I don't know why i loss period for 2months now. this situation happened to me 5yrs ago. A doctor told me that because of the climate change(weather changes in a way that in the morning the sun was shinny but in the evening, it will start to rain, vice versa) that cause the irregularity of my period. I need help. Been thinking about this for a month now. I want a regular period. :( please respond.