These are probably hemorrhoids
. Hemorrhoids are dilated veins around the anus and rectum that are quite common. They often show up during pregnancy because the additional back pressure on the pelvic blood vessels causes them to swell. They are also made worse by constipation and other things that cause a lot of straining with bowel movements. When hemorrhoids get very inflamed, they can bleed, and this is probably why you have noticed blood in your bowel movements.
Many minor cases of hemorrhoids can be treated by working on treating constipation, as this tends to be the main driver of the condition after the pregnancy is over. You can do this by drinking lots of fluids and eating lots of fruits and fiber. If you still have straining, a gentle laxative like Miralax may also help.
If however you develop worsening itching or pain in the hemorrhoids this might be an indication to see your primary care doctor
. Sometimes the hemorrhoids will become inflamed enough that blood clot forms inside them; this can be very painful, and it can require lancing of the inflamed vein. There are also steroid and anti itch medications that can be applied to help reduce the inflammation.