Hi dear and thanks for your query.
If you have forgot to take birth control pill two times within 8 days ,you had been unprotected during the time you have had intercourse .
You can use unwanted pill within 72 hours of unprotected intercourse
Hence you can wait until morning to buy the pill.
Another time please be regular while you are using birth control pill because :
1.you may have hormonal
imbalances causing irregular vaginal bleeding
2.you have the risk of unwanted pregnancy
All the best