I need some opinions please :)?

So my husband & I have a 10 month old boy who is the light of our lives! Our plan is to try for another baby in 6 months so when he/she is born our son will be 2. Also I'm a teacher so the summer off would allow more time with the new baby. Currently our financial situation is very tight...however I am hoping to take a full day teaching position in august(=double my income) & my husband is hoping for a promotion around the same time (=double income as well). My problem is last night we had sex & towards the end did not use a condom & I'm not on birth control. If we got pregnant we would not in any way be upset...but we are not ready. I know we could find a way to make it work but my husband said if I want he will buy the plan b pill...I feel torn on to take it or not? What would you do?