Own position is shown on the map when the map component did mount.

src/components/UserMap.js

@@ -2,15 +2,33 @@ import React, { Component } from 'react';
 import { Map, TileLayer, Marker, Popup } from 'react-leaflet';
 
 class UserMap extends Component {
+  constructor(props){
+    super(props);
+    this.state = {
+      ownLat: null,
+      ownLng: null,
+    }
+  }
+
+  componentDidMount(){
+    this.getCurrentPosition((position) => {
+      if(position != null){
+        this.setState({
+          ownLat: position.lat,
+          ownLng: position.lng,
+        });
+      }
+    });
+  }
 
-  getCurrentPosition(){
+  getCurrentPosition(callback){
     if(!navigator.geolocation){
       console.log("Can't get geolocation :/");
-      return null;
+      callback(null);
     }
     else{
-      navigator.geolocation.getCurrentPosition((position)=>{
-        return ({
+      navigator.geolocation.getCurrentPosition((position)=> {
+        callback({
           lat: position.coords.latitude,
           lng: position.coords.longitude
         });
@@ -30,6 +48,7 @@ class UserMap extends Component {
             Se on perjantai, my dudes <br />
           </Popup>
         </Marker>
+        {this.state.ownLat !== null && <Marker position={[this.state.ownLat, this.state.ownLng]}></Marker>}
       </Map>
     );
   }