Hey there,
with any version of the birth control pill it's safe to have sex any time during the month as long as you are consistant with taking the pills. If you take them every day at almost the same time, then you should have no concern about getting pregnant.
But if this is your first month on the pill, they say you should still use another form of birth control (such as a condom) beause your body needs time to adjust. But after the first month, you're clear to have sex any time without any worry at all.
As for wehther it's the combination or the mini pill...I have no idea. I don't know what the mini pills is. But I would assume it's the combination because it's not one hormone that you listed was in the pill. But please don't take my word on that, I have no idea. I'm in canada so we have different brands and different terms for them.
But anyway....As for the discharge, i'm not sure it's yeast infection. From what I understand with a yeast infection you'll usually have more irritation. Like itching and stuff. So if you aren't experiencing that, it could just be an initial reaction to the pill. Usually it takes about 3 months for the body to fully adjust to the pill. After that things should normalize more.
I hope this helps to answer your questions.
Take care,
~jenna