When is it okay to use the expectant mothers parking?

amber

at my local super marker theres a parking space designated for expactant mothers. theres never any one ever parked there. ever since the day after i got pregnant my boyfreind has been trying to park there but i never let him just incase a mother that actually needs the space comes along. however, last night while making a trip for some night time cravings i was tempted to use the space but felt guilty. im 17 weeks and not showing at all and dont nessecarily need the space, but when its 40 degrees out and rain/snowing, its tempting to use. with all of that, im only 17 so i'd hate for someone to think im just a rude teen taking the spot because its open. whats your opinion? would you be angry if you saw someone who didnt nessecarily need the spot using it? am i just over thinking it?