what is this!!!??

I went to my first appointment yesterday and everything went really good. I'm expecting identical twins and I seen both heartbeats. They gave me metronidazole gel because I have  a bacterial infection. I'm supposed to take one every night before I go to bed for 5 days. Last night was my first night taking it. This is my discharge today and it has me worried. My discharge has never been clumpy and that dark. Is it because I took that medicine and the bacteria is coming out or is it something worse?? Please help...