Advice please

Me and my S/O have been trying for a baby and recently my breasts have enlarged quite a bit, I'm also getting little lumps on the dark skin around my nipples which have recently become more prominent, my tummy has grown a tiny bit  although I'm not eating anymore than I use to and my breasts are sore so I took a PT which came back negative and then I started my period although it was a lot different to normal (length, flow, ect)  any ideas why?