Not on BC but might need to take Plan B

So my boyfriend and I have been together for a little over a year now and have been sexually actively the whole time. About a month ago he said that he would be more comfortable if I got on birth control before we continued having sex anymore. We had talked about it before but I just had never gone through and gotten it because we used condoms and withdrawal/pulling out.

This morning we had sex and he pulled out once and so I thought he finished but then he went back in. He told me he didn’t completely finish the first time so he came a little bit and then went back in and then pulled back out to finish. He said it would be good if I got Plan B just in case since he did come a little bit that first time.

I would just like some thoughts and reassurance on taking Plan B since I’ve never taken it before and he works all day today so I’m kind of doing this alone 😓

AND I AM GETTING BC ASAP!!!!