Help girls! Don't want t come to conclusions just yet!

Nina • 21, mother of serenity 💕, and happily in a relationship.
Hey guys so I need your help. I had my period about 2 weeks. Usually my breasts would start to hurt about a week before my period starts, but this time my brewers are full blast sore right now a week and a half after my period. Which is strange to me. I also had sex while on my period and I know a lot of people are telling me that getting pregnant when you have sex while on your period is very unlikely but has happened. But It ended a couple days after we had sex. I also know that sperm could last for a few days inside of you.. My breasts are super sore and swollen and I have been getting nausea lately. No throwing up but just nausea mostly after eating something. My desire for candy and sweet stuff is gone and i don't know... A lot of things with my body seem to be very weird and off right now... I Need a little help figuring out what's happening? Before I get to pregnancy  concerns I need help figuring out What else might be happening.... Unless there aren't anything that could be in that case....