All the symptoms, no peace of mind

I've been on BC (oral) for three years, I tend to miss days quite often, and my and my boyfriend have been having unprotected sex for sometime. We are moved in together, both have jobs and planning on starting a family very soon anyway, we're just hoping to get a little more settled in first. So lately I've noticed my abdomen feeling quite bloated, and hard (the very middle is a little more harder than the rest). I've been getting what feels like menstrual cramps even though my period is nowhere near, lower back pain, increased trips to the bathroom, slight nausea, I always have to have a bottle of water around, changes in my apettite, my gums have bled on one occation while brushing my teeth (this has never happened before), boobs feel fuller and a little harder, and today I've been feeling very moody. Now heres where I get confused. I did get my period earlier this month, but it was two days late and when it finally did start it was lighter than usual, so having some suspicion I went out and bought a HPT ...but ended up getting a neg. result. Whats up with that? If anyone has any advice or could give me any peace of mind it would be greatly appriciated.