Spotting at 5 weeks?

Hello mga mommies, I had a positive pregnancy test last week. My doctor gave an ultrasound request for confirmation and viability of my pregnancy and sa Monday pa yung balik ko. This is my second pregnancy na rin. Kagabi, nag spotting ako ng light brown, siguro mga 5 drops? Then kanina reddish orange naman pero mas konti. Medyo sumasakit din puson ko pero very mild lang naman so tolerable naman. Maybe kasi constipated din ako kaya ganun. Hindi ko kasi naranasan yung spotting sa first baby ko, Normal lang kaya to mamshies? Natatakot kasi ako lalo na at may enlarged thyroid ako according din sa thyroid ultrasound ko. ?