Hi Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern.
Yes
Levonorgestrel could alter the menstrual cycle. It has side effect or delaying menstrual period & also altering it. Actually levonorgestrol should be used as emergency
contraceptive pill( to prevent unwanted pregnancy in case of emergency only). It should not be used as regular method of
contraception.
You have now taken 2 dose of Levonorgestrel within a week, which was not advised. You should aspect some irregularity in your periods. This effect could take 1 or more cycles to get to normal.
Use condom or regular contraceptive pill as method of contraception in future. Taking more emergency contraceptive pills can cause problems like
irregular periods, ovarian hyper-stimulation syndrome & even
infertility.
You should also do a pregnancy test to rule-out pregnancy possibility, as not method of contraception is 100% effective
For more queries consult a gynaecologist
Hope this information helps