Can You Make Up Missed Fasts during Tashriq Days?
Question

I decided without any knowledge of Tashriq to complete the fasting of Ramadan. Do I count the 2 of the 3 days of Tashriq that I started fasting or must I start counting my ten days (due to menses and illness) after Tashriq?
Praise be to Allah.Is it permissible to fast the Days of Tashriq?
The days of Tashriq are the three days following `Eid Al-Adha , namely the 11th, 12th and 13th of Dhul-Hijjah. It is prohibited to fast on these days . 
The Prophet (peace and blessings of Allah be upon him) said: “The days of Tashriq are the days of eating and drinking.” (Narrated by Muslim, 1141, from the Hadith of Nubayshah Al-Hadhali (may Allah be pleased with him)) 
And he (peace and blessings of Allah be upon him) said: “The day of `Arafah, the day of Sacrifice (An-Nahr) and the days of Tashriq are our `Eid, us Muslims, and they are days of eating and drinking. (Narrated by An-Nasa’i , 3004; At-Tirmidhi, 773; Abu Dawud, 2419 – from the Hadith of `Uqbah ibn `Amir (may Allah be pleased with him). THe Hadith was classed as authentic by Al-Albani in Sahih Abu Dawud.) 
The Prophet (peace and blessings of Allah be upon him) did not grant a concession allowing anyone to fast on these three days except for the pilgrims performing Tamattu` or Qiran types of Hajj, who did not have sacrificial animal with them. 
Al-Bukhari (1998) narrated that `Aishah and Ibn `Umar (may Allah be pleased with them) said: “No one was allowed to fast on the days of Tashriq except the (pilgrim) who did not have a sacrificial animal.” 
Can you make up missed fasts during Tashriq days?
The majority of scholars said that it is not permissible to fast on the Days of Tashriq, regardless of whether that is an optional fast, making up a missed fast or fasting in fulfillment of a vow. They said that a fast was invalid if it was observed during this time. 
The most correct view is that of the majority, and there are no exceptions except in the case of the pilgrim who does not have a sacrificial animal. 
Shaykh Ibn Baz (may Allah have mercy on him) said: 
“Similar fasts should not be observed on the day of `Eid Al-Adha or the Days of Tashriq, because the Messenger of Allah (peace and blessings of Allah be upon him) forbade that. But there is evidence that it is permissible to fast on the days of Tashriq for the pilgrim performing Tamattu` or Qiran Hajj in lieu of offering the sacrifice, especially those who are unable to offer the sacrifice. But fasting them on a voluntary basis or for any other reason is not permissible, as in the case of `Eid.” (Fatawa Ramadan, compiled by Ashraf `Abd Al-Maqsud, p. 716) 
Shaykh Ibn `Uthaymin (may Allah have mercy on him) said: 
“It is permissible for the pilgrim performing Tamattu` or Qiran, if he cannot find a sacrificial animal, to fast these three days so that he can fast them during the Hajj season. But apart from that it is not permissible to fast these days; even if a person is fasting two consecutive months, he must not fast on the day of `Id and the three days that follow it, then he should resume his fasting.” (Fatawa Ramadan, p. 727) 
Based on this, the fasts that you observed on the Days of Tashriq to make up for missed Ramadan fasts, are not valid, and you must repeat them. 
When making up missed Ramadan fasts, the days need not be consecutive , so you can make up the missed fasts on consecutive days or on separate days. 
And Allah knows best.