Anak, please go see your OB as soon as you can, kahit this week pa lang, especially since it's been 3 weeks na and you're 13 weeks pregnant na. Ang prolonged pain like that, lalo na kapag negative sa UTI pero nag-persist pa, needs proper checking kasi baby's safety comes first. A few of my mum friends had similar scares, at honestly, better safe than sorry talaga, walang hassle ang quick check-up compared sa worry, di ba? Your doctor needs to know the full picture, kung kailan exactly ang sakit, kung ano na-try mo na. Don't wait pa, mommy, especially with the morning attacks mo.