Side affects of the Pill?

So I’ve been on the combined pill for almost 2 months he first month or so went fine but for the past week or two I’ve had recurring headaches and nausea and dizzy spells, up to the point where last weekend I almost fainted and then was vomiting in the evening and still felt nauseous in the morning. To begin with the dizzy spells were mostly just after sex though have now become more regular. As well as this, I know the pill can cause irregular periods but mine have been pretty out of whack- normal 5day period and 4 week break before the pill then ended up with an 11 day period and 2 weeks later a week long period and 2 weeks after I’ve come on again (yesterday after sex). Could the symptoms be because of the pill or something else??