Help!!

So lastnight I got drunk with some friends and a person I thought was a friend agreed to take me home instead he acted like he was helping me in the car and ended up pulling my dress up and inserting himself inside of me I pushed him off, this happened around 1am this morning actually.

This morning I went to get the prep pills (pre-exposure Prophylaxis) it’s used just in case you may have been exposed to HIV. (I’m a health nut and I panicked he claims he’s clean but you can never be too sure.

The problem is the Pharmacy only had one which is the Tivicay idk if there any doctors or nurses here but is it okay to take just the one until my order is filled on Monday morning ? Or will it be too late? It’s most effective if taken is 72 hours.