Have armpit lump. Radiating pain in arm.

Is my armpit lump sign of breast cancer? When I woke up the morning of 13th Nov, I had a painful armpit lump.I had also started my periods one night before - the night my lump started coming. It was small and hardened and my armpit was aching when I was raising my hand. I didn't wax or shave or have ingrown hair issue. A family doctor asked me if I had raised something heavy, and yes, I was regularly lifting a heavy suitcase everyday to take out some clothes. I took some homeopathic meds and it settled down a lot in 3 days By 16th, it was almost nowhere. However, my left arm was aching. I couldn't rest it much , the pain was radiating and I could feel stiff muscle/tendon in my armpit I check again and felt a small hard lump when I push way into my armpit. It's probably attached to my muscle as much as I can feel. But definitely not a protruding lump. Have a history of breast cancer (my grandma had it) so I'm anxious. Is it just a muscular thing or something serious?