Mazal tov on the recent birth of your baby!
Unfortunately, it is common to experience irregular staining after weaning, due to the changes in hormone levels in your body.
Your
hefsek taharah from Friday remains valid. The stains found on the
(disposable) pantyliner did not invalidate your
clean days. However, since you didn't perform a
bedikah on Shabbat, you may not count that day as day 1 of the clean days. Your
bedikah on Sunday counts as your new day 1, and assuming you are able to complete the clean days, you are scheduled to immerse Motzai Shabbat.
Since disposable pantyliners are a surface that is not susceptible to
tum'ah, and
stains found on them may be disregarded, it is preferable not to wear them during the clean days. Please see our
posted question on the topic for a more detailed discussion.
Since the staining you are experiencing is causing difficulty completing the clean days, you may reduce the number of
bedikot required. You already performed a
hefsek and a day 1
bedikah, so you should just perform one more
bedikah on one of the intermediate clean days (days 2-6) as well as a final
bedikah on day 7.
You should also change your white underwear (or pantyliners) more frequently to prevent any staining from accumulating to the size of a
k'gris (approximately the size of a US dime or Israeli shekel coin).
Even if you will only have a week or so after immersion before your next period, we still highly recommend that you try to complete the
taharah process and immerse. It is possible that your cycle will still be irregular at this point, so you may have more time left than you expect. However, ultimately it is up to you and your husband, and if you agree that your situation is too frustrating, you can jointly decide to skip mikveh this month.
Please feel free to get back to us with any further questions.
B'hatzlacha!