Mazal tov on the recent birth of your baby!
While many women are able to get to mikveh by 6-8 weeks postpartum, it is also normal for it to take longer for the bleeding to subside to the point where it is possible to count seven clean days.
Even if this bleeding is dam makkah (which it possibly is), you still need acceptable bedikot (minimally a hefsek taharah and one bedikah each on days 1 and 7), which is difficult while you are actively bleeding. If the bleeding is erratic, and you are able to perform this minimum number of bedikot, you may disregard any other stains found and omit the rest of the bedikot. As long as you have an acceptable hefsek and day 1 and day 7 bedikot, you may immerse. However, if the bleeding occurs daily and you can't get acceptable bedikot, unfortunately, this means that you just have to give your body more time and wait for the bleeding to ease up. Once the bleeding is no longer reddish, you may attempt a hefsek taharah. Stains found on a hefsek or bedikah that are light brown (the color of coffee with milk) with no reddish hue are acceptable. Other shades of brown can be brought to a halachic authority for evaluation, explaining your situation.
If the bleeding has not subsided within another week or two we recommend going back to your doctor for a follow up.
Please feel free to get back to us with any further questions.
B'Hatzlacha!