Pregnancy from pre cum?

Me and Boyfriend slowly stopped using condoms and have been having unprotected sex for a month now. He always pulls out and we've never had any accidents. But I wonder if it's possible for him to pre cum and not know it? Because lately my Breast seem swollen and a little tender. I've been super tired lately. And for the past few days I've had really weird thick cm. like its white and comes out and forms squishy gel like balls that come out after I've been laying down for a period of time and I'll find like one or two in between my inner thighs. I don't know if that's normal? I still have a week till my period is suppose to start but it's making me so nervous not knowing! I don't know if this sounds dumb or not. I waited for the right person and have only been sexually active for 2 months now. So this is all very new to me!