All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
That you intended Ihraam when you were close to the Miqaat was obligatory. If you, however, continued to wear the form-fitting clothes after having had the intention for Ihraam, then you are liable to a Fidyah (ransom). Thus, you need to either slaughter a sheep, feed six needy person half a Saa‘ for each, or fast three days. You can choose from among these three options and once you do any of them you have cleared your liability. Also, you are not bearing a sin if you did not intentionally continue to wear the form-fitting clothes after having the intention for Ihraam.
Allaah Knows best.