Diagnosed with PCOS / PCOD. Or pcod?

So recently i had been having Extremely delayed periods (i had to induce them using meds), weight gain and extreme hair loss. I didnt gain weight easily so 5 kgs in 3 months freaked me out. I got appointments w a gynecologist, and pcos/pcod showed up in my sonography (enlarged ovaries that appear to be polycystic- sonography report) I had a sonography 6 months prior to this one (due to extremely painful periods) but nothing was wrong back then. My gynac suggested a birth control pill, i took it for two days but it was horrible for me. I threw up after almost every meal i ate, had a constant headache, and horrible stomach ache at night. Yesterday was the third day but i stopped taking them, and I'm feeling much better. I want to know if its better to consult with an endocrinologist or a gynaecologist in case of pcos/pcod. Also what is the major difference between the two? And how can you tell if its pcos or pcod?