You need to POAS. We can't tell if you are pregnant or not, only a test can. Also, if your BF isn't totally on board with getting pregnant, then you need to use protection.
Also, my periods got lighter and I started experiencing lower back pain after I stopped birth control. That's my new normal for PMS/AF. Did you recently get off the pill? That can make things weird for a while.
Other than that, try not to read too much into anything. If you think you're pregnant, take a test. If it's negative, you're either not pregnant or it's too early. Keep testing once a week until AF, a BFP, or CD60. If you hit CD60, call your doctor.
That's all any of us can really tell you.