Feeling strange

I have a 5 month old son. He was born November 25, 2017. I did have unprotected sex up until I got on birth control January 4th.

I’ve been vomiting everyday and I’m super nauseous every time I eat. This has been the past 2 weeks. I’ve seen spotting but I haven’t had a period since I got pregnant March 1st 2017.

I feel like I am pregnant again. All test are negative tho.

When my mom was pregnant with me she didn’t know until she was 5 months in. She was on Depo and had 2 shots before her test came back positive. I’m scared it the same situation with me.