Sertraline for 3.5 weeks side effects

I have been on 50mg of sertraline for 3 1/2 weeks, is it normal to just now begin having nausea, slight lightheaded, headaches, & fatigue? I didn’t have much side effects when I first started the medication, up until about a week ago. Also I’ve been getting really hot easily lately.

Nausea is common first few weeks gradually symptoms will dissappear headaches are common also and light headed