trans v

hello regular po menstruation ko. sept. yung last , october spotting nalang feel ko bubtis since regular din at s pt meron isang 2lines though malabo ung isang line.. then we decided n pmunta ng ob, since spotting hatol sakin trans v ultrasound, then pgkita dun wla pa kahit ano kahit gsac wla, ang tanging nakita lng ay mga dugo.. any idea ano po yung dugo na yun ? follow up trans v ulit ako after 2weeks.. mejo worry lng po pero ngayon no spotting nako November.. and no back pain nadin and cramps ng puson.. hindi din ako nakaranas ng severe pain .. as in very light lng..