Aduh, sakit perut lama macam ni memang payah kan, terutama kalau dah check dengan doktor pun still ada batu dalam bladder, definitely kena follow up lagi, especially since the pain hasn't gone away after your period. Since you're having bloating, cramping, and that back pain (and the pregnancy test is negative), I'd suggest balik jumpa doktor or maybe get a second opinion, sebab batu kencing kecil pun boleh cause ongoing discomfort, or ada benda lain yang perlu di-investigate. A few of my mum friends had similar persistent stomach issues dan rupanya ada other things going on, so jangan amik ringan lah, better to get it sorted properly daripada terus sakit macam ni.