Almost 16...early signs?

Alexis
I have been dating my current boyfriend for almost 5 months, he is honestly the best thing that is happened to me. He is the only person I've had sex with, and when we first started having sex we use protection and always got Plan B if we werent using a condom. We are very open with each other, we have talked about the chances of me getting pregnant and what would happen if I did( we would keep it). Now we have stopped using condoms(we really dislike them) we use the "pullout method" now. This isnt really the question I have but just wanted to give a backstory.( please don't respond with anything about me being a teen and being possibly pregnant, that is not the question!)
So I had my period but a week later I had another but for only 4 days rather than the regular 6 or 7. Now I have been having cramps (never usually happen after my period) Haven't been hungry at all (like I don't want to eat and my boyfriend has to force me to eat), and haven't been really motivated to do anything( not depressed just really lazy).
My boobs have not been in any discomfort though and haven't gotten bigger at all. Only a bit of back pain .
Are these possible early signs ??