My periods have always been fairly guessable, and monthly. I am sexually active with one partner, my boyfriend, and I do not take birth control or anything like that. I am 19 years old and struggle to keep my low weight at a stable, "healthy" number.

Here is the problem:

Recently (starting around October), my periods have been strange. They have been occurring multiple times within a month (last month it felt like I was having one every other week. There was no pain or extra cramping or anything, just normal period blood sometimes light and sometimes normal. 

This month my period came on as usual, and it ended as usual. The next week I noticed small traces of blood in my underwear like a small stain, and thought it was probably the last bits getting out of my system. I took a Tylenol for a few days until it stopped because there was some abdominal discomfort. In the days following there were some friendship/relationship problems that caused a lot of stress, a horrible bout of constipation, and I tried fingering myself for the very first time. Come this week, the week of Christmas,  I noticed a small amount of bleeding yet again, though it was different. It looked like old blood but didn't have any bits in it like my period blood would. It also stopped that very same day.

Today, the bleeding started up yet again, and I noticed it had a really strange smell. It didn't smell like period blood at all. It had a weird, bad smell that I'd never experienced before. I've been wearing pads all day. It's really embarrassing and I'm afraid to have sex in case it makes things worse.

I have no history of medical conditions or infections, and when I was last checked out, at the beginning of the year everything was normal. I did get a vaccination I think for hpv or meningitis and forgot to go back to take the second shot, but that was months ago. I've never been to a gynecologist, and I want to go to the clinic and make an appointment, but I don't have that kind of money and I'm not insured.

Is this something that's normal? Is this one of those things that clears itself up over time, or do I need some kind of medication that I can only get from a doctor? Do you think it could be really serious? I'm honestly very scared about it, but like I said, my family doesn't have that kind of money and I'm not insured, so if it's something I won't need a doctor for then I'd prefer not to go.